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Objectives: We sought to investigate the impact of sex on myocardial perfusion changes following chronic total coronary occlusion (CTO) percutaneous coronary intervention (PCI) as measured by [ 15 O]H 2 O positron-emission tomography (PET) perfusion imaging., Background: CTO PCI has been associated with an increase in myocardial perfusion, yet females are less likely to undergo revascularization. As such, data on the impact of sex on myocardial perfusion following CTO PCI is scarce., Methods: A total of 212 patients were prospectively enrolled and underwent CTO PCI combined with [ 15 O]H 2 O PET perfusion imaging prior to and 3 months after PCI. Hyperemic myocardial blood flow (hMBF, mL·min -1 ·g -1 ) and coronary flow reserve (CFR) allocated to the CTO territory were quantitatively assessed., Results: This study comprised 34 (16 %) females and 178 (84 %) males. HMBF at baseline did not differ between sexes. Females showed a higher increase in hMBF than males (Δ1.34 ± 0.67 vs. Δ1.06 ± 0.74, p = 0.044), whereas post-PCI hMBF was comparable (2.59 ± 0.85 in females vs. 2.28 ± 0.84 in males, p = 0.052). Female sex was independently associated with a higher increase in hMBF after correction for clinical covariates. CFR increase after revascularization was similar in females and males (Δ1.47 ± 0.99 vs. Δ1.30 ± 1.14, p = 0.711)., Conclusions: The present study demonstrates a greater recovery of stress perfusion in females compared to males as measured by serial [ 15 O]H 2 O PET imaging. In addition, a comparable increase in CFR was found in females and males. These results emphasize the benefit of performing CTO PCI in both sexes., Clinical Perspective: What is new? What are the clinical implications?, Competing Interests: Declaration of competing interest Nothing to disclose., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Same-day discharge (SDD) in patients undergoing percutaneous coronary intervention (PCI) of a chronic total occlusion (CTO) is appealing because of the increased patient comfort. However, data on SDD following large-bore vascular access are scarce., Aims: We investigated the feasibility and safety of SDD in patients undergoing large-bore CTO PCI., Methods: Between 2013 and 2023, 948 patients were prospectively enrolled in a single-centre CTO registry and underwent CTO PCI. SDD was pursued in all patients. Large-bore access was defined as the use of ≥7 French (Fr) sheaths in ≥1 access site. A logistic regression analysis was used to identify predictors for non-SDD. Clinical follow-up was obtained at 30 days., Results: SDD was observed in 62% of patients. Large-bore access was applied in 99% of the cohort. SDD patients were younger and more often male, with lower rates of renal insufficiency and prior coronary artery bypass grafting. Local access site bleeding (odds ratio [OR] 8.53, 95% confidence interval [CI]: 5.24-13.87) and vascular access complications (OR 7.23, 95% CI: 1.98-26.32) made hospitalisation more likely, with vascular access complications occurring in 3%. At 30 days, the hospital readmission rate was low in both SDD and non-SDD patients (5% vs 7%; p=non-significant). Finally, SDD was not a predictor for major adverse cardiovascular events (MACE) at follow-up., Conclusions: Same-day discharge can be achieved in the majority of patients undergoing CTO PCI with large-bore (≥7 Fr) access. Similar low hospital readmission and MACE rates between SDD and non-SDD patients at 30 days demonstrate the feasibility and safety of SDD.

In patients evaluated for obstructive coronary artery disease (CAD), guidelines recommend using either fractional flow reserve (FFR) or instantaneous wave-free ratio (iFR) to guide coronary revascularization decision-making. The hemodynamic significance of lesions with discordant FFR and iFR measurements is debated. This study compared [ 15 O]H 2 O PET-derived absolute myocardial perfusion between vessels with concordant and discordant FFR and iFR measurements. Methods: We included 197 patients suspected of obstructive CAD who had undergone [ 15 O]H 2 O PET perfusion imaging and combined FFR/iFR interrogation in 468 vessels. Resting myocardial blood flow (MBF), hyperemic MBF, and coronary flow reserve (CFR) were compared among 4 groups: FFR low/iFR low ( n = 79), FFR high/iFR low ( n = 22), FFR low/iFR high ( n = 22), and FFR high/iFR high ( n = 345). Predefined [ 15 O]H 2 O PET thresholds for ischemia were 2.3 mL·min -1 ·g -1 or less for hyperemic MBF and 2.5 or less for CFR. Results: Hyperemic MBF was lower in the concordant low (2.09 ± 0.67 mL·min -1 ·g -1 ), FFR high/iFR low (2.41 ± 0.80 mL·min -1 ·g -1 ), and FFR low/iFR high (2.40 ± 0.69 mL·min -1 ·g -1 ) groups compared with the concordant high group (2.91 ± 0.84 mL·min -1 ·g -1 ) ( P < 0.001, P = 0.004, and P < 0.001, respectively). A lower CFR was observed in the concordant low (2.37 ± 0.76) and FFR high/iFR low (2.64 ± 0.84) groups compared with the concordant high group (3.35 ± 1.07, P < 0.01 for both). However, for vessels with either low FFR or low iFR, quantitative hyperemic MBF and CFR values exceeded the ischemic threshold in 38% and 49%, respectively. In addition, resting MBF exhibited a negative correlation with iFR ( P < 0.001) and was associated with FFR low/iFR high discordance compared with concordant low FFR/low iFR measurements, independent of clinical and angiographic characteristics, as well as hyperemic MBF (odds ratio [OR], 0.41; 95% CI, 0.26-0.65; P < 0.001). Conclusion: We found reduced myocardial perfusion in vessels with concordant low and discordant FFR/iFR measurements. However, FFR/iFR combinations often inaccurately classified vessels as either ischemic or nonischemic when compared with hyperemic MBF and CFR. Furthermore, a lower resting MBF was associated with a higher iFR and the occurrence of FFR low/iFR high discordance. Our study showed that although combined FFR/iFR assessment can be useful to estimate the hemodynamic significance of coronary lesions, these pressure-derived indices provide a limited approximation of [ 15 O]H 2 O PET-derived quantitative myocardial perfusion as the physiologic standard of CAD severity., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

Aims: In chronic coronary syndrome (CCS) patients with documented coronary artery disease (CAD), ischaemia detection by myocardial perfusion imaging (MPI) and an invasive approach are viable diagnostic strategies. We compared the diagnostic performance of quantitative flow ratio (QFR) with single-photon emission computed tomography (SPECT), positron emission tomography (PET), and cardiac magnetic resonance imaging (CMR) in patients with prior CAD [previous percutaneous coronary intervention (PCI) and/or myocardial infarction (MI)]., Methods and Results: This PACIFIC-2 sub-study evaluated 189 CCS patients with prior CAD for inclusion. Patients underwent SPECT, PET, and CMR followed by invasive coronary angiography with fractional flow reserve (FFR) measurements of all major coronary arteries (N = 567), except for vessels with a sub-total or chronic total occlusion. Quantitative flow ratio computation was attempted in 488 (86%) vessels with measured FFR available (FFR ≤0.80 defined haemodynamically significant CAD). Quantitative flow ratio analysis was successful in 334 (68%) vessels among 166 patients and demonstrated a higher accuracy (84%) and sensitivity (72%) compared with SPECT (66%, P < 0.001 and 46%, P = 0.001), PET (65%, P < 0.001 and 58%, P = 0.032), and CMR (72%, P < 0.001 and 33%, P < 0.001). The specificity of QFR (87%) was similar to that of CMR (83%, P = 0.123) but higher than that of SPECT (71%, P < 0.001) and PET (67%, P < 0.001). Lastly, QFR exhibited a higher area under the receiver operating characteristic curve (0.89) than SPECT (0.57, P < 0.001), PET (0.66, P < 0.001), and CMR (0.60, P < 0.001)., Conclusion: QFR correlated better with FFR in patients with prior CAD than MPI, as reflected in the higher diagnostic performance measures for detecting FFR-defined, vessel-specific, significant CAD., Competing Interests: Conflict of interests: J.H.R., R.A.K., and J.T. are employees of Medis Medical Imaging. J.K. received consultancy fees from GE Healthcare and AstraZeneca and speaker fees from GE Healthcare, Bayer, Lundbeck, and Merck. P.K. received research grants from HeartFlow Inc. All others have no conflict of interests to disclose., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: The Japanese Channel (J-Channel) score was introduced to aid in retrograde percutaneous coronary intervention (PCI) of chronic total coronary occlusions (CTOs). The predictive value of the J-Channel score has not been compared with established collateral grading systems such as the Rentrop classification and Werner grade., Aims: To investigate the predictive value of the J-Channel score, Rentrop classification and Werner grade for successful collateral channel (CC) guidewire crossing and technical CTO PCI success., Methods: A total of 600 prospectively recruited patients underwent CTO PCI. All grading systems were assessed under dual catheter injection. CC guidewire crossing was considered successful if the guidewire reached the distal segment of the CTO vessel through a retrograde approach. Technical CTO PCI success was defined as thrombolysis in myocardial infarction flow grade 3 and residual stenosis <30%., Results: Of 600 patients, 257 (43%) underwent CTO PCI through a retrograde approach. Successful CC guidewire crossing was achieved in 208 (81%) patients. The predictive value of the J-Channel score for CC guidewire crossing (area under curve 0.743) was comparable with the Rentrop classification (0.699, p = 0.094) and superior to the Werner grade (0.663, p = 0.002). Technical CTO PCI success was reported in 232 (90%) patients. The Rentrop classification exhibited a numerically higher discriminatory ability (0.676) compared to the J-Channel score (0.664) and Werner grade (0.589)., Conclusions: The J-channel score might aid in strategic collateral channel selection during retrograde CTO PCI. However, the J-Channel score, Rentrop classification, and Werner grade have limited value in predicting technical CTO PCI success., (© 2023 The Authors. Catheterization and Cardiovascular Interventions published by Wiley Periodicals LLC.)

Background and Aims: Myocardial perfusion imaging (MPI) and anatomical imaging with coronary computed tomography angiography (CCTA) can play an important role in the preprocedural planning of a chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We aimed to establish the feasibility of a novel dynamic computed tomography perfusion (CTP) analysis for the assessment of myocardial perfusion before and after a successful recanalization of CTO in patients undergoing CCTA as part of a standard preprocedural workup., Methods: In a prospective observational study symptomatic patients underwent dynamic CTP on a dual-source CT scanner both before and 3 months after successful CTO PCI., Results: Twenty-seven patients completed the study (63 ± 8 years old, 78% male). Following successful CTO PCI, there was a significant reduction in the ischemic burden (5 [5-7] versus 1 [0-2] segments, p < 0.001), and improvement in myocardial blood flow (85.3 [71.7-94.1] versus 134.6 [123.8-156.9] mL/min, p < 0.001) resulting in an increase in the relative flow reserve (0.49 [0.41-0.57] versus 0.88 [0.74-0.95], p < 0.001)., Conclusions: CTP emerges as a robust and safe method for MPI in CTO patients. The single imaging session assessment of both coronary anatomy and perfusion with CT lends itself to precise disease phenotyping in the challenging population of CTO patients., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Coronary flow capacity (CFC) is a measure that integrates hyperemic myocardial blood flow and coronary flow reserve to quantify the pathophysiological impact of coronary artery disease on vasodilator capacity. This study explores the prognostic value of modified CFC derived from [ 15 O]H 2 O positron emission tomography perfusion imaging., Methods: Quantitative rest/stress perfusion measurements were obtained from 1300 patients with known or suspected coronary artery disease. Patients were classified as having myocardial steal (n=38), severely reduced CFC (n=141), moderately reduced CFC (n=394), minimally reduced CFC (n=245), or normal flow (n=482) using previously defined thresholds. The end point was a composite of death and nonfatal myocardial infarction., Results: During a median follow-up of 5.5 (interquartile range, 3.7-7.8) years, the end point occurred in 153 (12%) patients. Myocardial steal (hazard ratio [HR], 6.70 [95% CI, 3.21-13.99]; P <0.001), severely reduced CFC (HR, 2.35 [95% CI, 1.16-4.78]; P =0.018), and moderately reduced CFC (HR, 1.95 [95% CI, 1.11-3.41]; P =0.020) were associated with worse prognosis compared with normal flow, after adjusting for clinical characteristics. Similarly, in the overall population, increased resting myocardial blood flow (HR, 3.05 [95% CI, 1.68-5.54]; P <0.001), decreased hyperemic myocardial blood flow (HR, 0.68 [95% CI, 0.52-0.90]; P =0.007) and decreased coronary flow reserve (HR, 0.55 [95% CI, 0.42-0.71]; P <0.001) were independently associated with adverse outcome. In a model adjusted for the combined use of perfusion metrics, modified CFC demonstrated independent prognostic value (overall P =0.017)., Conclusions: [ 15 O]H 2 O positron emission tomography-derived resting myocardial blood flow, hyperemic myocardial blood flow, coronary flow reserve, and CFC are prognostic factors for death and nonfatal myocardial infarction in patients with known or suspected coronary artery disease. Importantly, after adjustment for clinical characteristics and the combined use of [ 15 O]H 2 O positron emission tomography perfusion metrics, modified CFC remained independently associated with adverse outcome., Competing Interests: Disclosures None.

The ongoing opioid addiction crisis necessitates the identification of novel risk factors to improve prevention and treatment of opioid use disorder. Parental opioid exposure has recently emerged as a potential regulator of offspring vulnerability to opioid misuse, in addition to heritable genetic liability. An understudied aspect of this "missing heritability" is the developmental presentation of these cross-generational phenotypes. This is an especially relevant question in the context of inherited addiction-related phenotypes, given the prominent role of developmental processes in the etiology of psychiatric disorders. Paternal morphine self-administration was previously shown to alter the sensitivity to the reinforcing and antinociceptive properties of opioids in the next generation. Here, phenotyping was expanded to include the adolescent period, with a focus on endophenotypes related to opioid use disorders and pain. Paternal morphine exposure did not alter heroin or cocaine self-administration in male and female juvenile progeny. Further, baseline sensory reflexes related to pain were unaltered in morphine-sired adolescent rats of either sex. However, morphine-sired adolescent males exhibited a reduction in social play behavior. Our findings suggest that, in morphine-sired male offspring, paternal opioid exposure does not affect opioid intake during adolescence, suggesting that this phenotype does not emerge until later in life. Altered social behaviors in male morphine-sired adolescents indicate that the changes in drug-taking behavior in adults sired by morphine-exposed sires may be due to more complex factors not yet fully assessed., Competing Interests: Declaration of competing interest The manuscript has been approved by all authors and there are no conflicts of interest to report. Thank you for considering this article for publication in Molecular and Cellular Neuroscience., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Patients with prior coronary artery bypass grafting (CABG) frequently require repeat percutaneous revascularization due to advanced age, progressive coronary artery disease and bypass graft failure. Percutaneous coronary intervention (PCI) of either the bypass graft or the native coronary artery may be performed. Randomized trials comparing native vessel PCI with bypass graft PCI are lacking and long-term outcomes have not been reported., Methods: PROCTOR (NCT03805048) is a prospective, multicenter, randomized controlled trial, that will include 584 patients presenting with saphenous vein graft (SVG) failure and a clinical indication for revascularization, as determined by the local Heart Team. The trial is designed to compare the clinical and angiographic outcomes in patients randomly allocated in a 1:1 fashion to either a strategy of native vessel PCI or SVG PCI. The primary study endpoint is a 3-year composite of major adverse cardiac events (MACE: all-cause mortality, non-fatal target coronary territory myocardial infarction [MI], or clinically driven target coronary territory revascularization). At 3-years, after evaluation of the primary endpoint, follow-up invasive coronary angiography will be performed. Secondary endpoints comprise individual components of MACE at 1, 3 and 5 years follow-up, PCI-related MI, MI >48 hours after index PCI, target vessel failure, target lesion revascularization, renal failure requiring renal-replacement therapy, angiographic outcomes at 3-years and quality of life (delta Seattle Angina Questionnaire, Canadian Cardiovascular Society Grading Scale and Rose Dyspnea Scale)., Conclusion: PROCTOR is the first randomized trial comparing an invasive strategy of native coronary artery PCI with SVG PCI in post-CABG patients presenting with SVG failure., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Purpose of Review: This review will outline the current evidence on the anatomical, functional, and physiological tools that may be applied in the evaluation of patients with late recurrent angina after coronary artery bypass grafting (CABG). Furthermore, we discuss management strategies and propose an algorithm to guide decision-making for this complex patient population., Recent Findings: Patients with prior CABG often present with late recurrent angina as a result of bypass graft failure and progression of native coronary artery disease (CAD). These patients are generally older, have a higher prevalence of comorbidities, and more complex atherosclerotic lesion morphology compared to CABG-naïve patients. In addition, guideline recommendations are based on studies in which post-CABG patients have been largely excluded. Several invasive and non-invasive diagnostic tools are currently available to assess graft patency, the hemodynamic significance of native CAD progression, left ventricular function, and myocardial viability. Such tools, in particular the latest generation coronary computed tomography angiography, are part of a systematic diagnostic work-up to guide optimal repeat revascularization strategy in patients presenting with late recurrent angina after CABG., (© 2022. The Author(s).)

Background: Revascularisation of a chronic total coronary occlusion (CTO) impacts the coronary physiology of the remote myocardial territory., Aims: This study aimed to evaluate the intrinsic effect of CTO percutaneous coronary intervention (PCI) on changes in absolute perfusion in remote myocardium., Methods: A total of 164 patients who underwent serial [ 15 O]H 2 O positron emission tomography (PET) perfusion imaging at baseline and three months after successful single-vessel CTO PCI were included to evaluate changes in hyperaemic myocardial blood flow (hMBF) and coronary flow reserve (CFR) in the remote myocardium supplied by both non-target coronary arteries., Results: Perfusion indices in CTO and remote myocardium showed a positive correlation before (resting MBF: r=0.84, hMBF: r=0.75, and CFR: r=0.77, p<0.01 for all) and after (resting MBF: r=0.87, hMBF: r=0.87, and CFR: r=0.81, p<0.01 for all) CTO PCI. Absolute increases in hMBF and CFR were observed in remote myocardium following CTO revascularisation (from 2.29±0.67 to 2.48±0.75 mL·min -1 ·g -1 and from 2.48±0.76 to 2.74±0.85, respectively, p<0.01 for both). Improvements in remote myocardial perfusion were largest in patients with a higher increase in hMBF (β 0.58, 95% CI: 0.48-0.67, p<0.01) and CFR (β 0.54, 95% CI: 0.44-0.64, p<0.01) in the CTO territory, independent of clinical, angiographic and procedural characteristics., Conclusions: CTO revascularisation resulted in an increase in remote myocardial perfusion. Furthermore, the quantitative improvement in hMBF and CFR in the CTO territory was independently associated with the absolute perfusion increase in remote myocardial regions. As such, CTO PCI may have a favourable physiologic impact beyond the intended treated myocardium.

Aims: Coronary flow capacity (CFC) integrates quantitative hyperaemic myocardial blood flow (hMBF) and coronary flow reserve (CFR) to comprehensively assess physiological severity of coronary artery disease (CAD). This study evaluated the effects of revascularization on CFC as assessed by serial [15O]H2O positron emission tomography (PET) perfusion imaging., Methods and Results: A total of 314 patients with stable CAD underwent [15O]H2O PET imaging at baseline and after myocardial revascularization to assess changes in hMBF, CFR, and CFC in 415 revascularized vessels. Using thresholds for ischaemia and normal perfusion, vessels were stratified in five CFC categories: myocardial steal, severely reduced CFC, moderately reduced CFC, minimally reduced CFC, and normal flow. Additionally, the association between CFC increase and the composite endpoint of death and non-fatal myocardial infarction (MI) was studied. Vessel-specific CFC improved after revascularization (P < 0.01). Furthermore, baseline CFC was an independent predictor of CFC increase (P < 0.01). The largest changes in ΔhMBF (0.90 ± 0.74, 0.93 ± 0.65, 0.79 ± 0.74, 0.48 ± 0.61, and 0.29 ± 0.66 mL/min/g) and ΔCFR (1.01 ± 0.88, 0.99 ± 0.69, 0.87 ± 0.88, 0.66 ± 0.91, and -0.01 ± 1.06) were observed in vessels with lower baseline CFC (P < 0.01 for both). During a median follow-up of 3.5 (95% CI 3.1-3.9) years, an increase in CFC was independently associated with lower rates of death and non-fatal MI (HR 0.43, 95% CI 0.19-0.98, P = 0.04)., Conclusion: Successful revascularization results in an increase in CFC. Furthermore, baseline CFC was an independent predictor of change in hMBF, CFR, and subsequently CFC. In addition, an increase in CFC was associated with a favourable outcome in terms of death and non-fatal MI., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Aims: To compare cardiac magnetic resonance (CMR) measurement of T1 reactivity (ΔT1) with [15O]H2O positron emission tomography (PET) measurements of quantitative myocardial perfusion., Methods and Results: Forty-three patients with suspected obstructed coronary artery disease underwent [15O]H2O PET and CMR at 1.5-T, including rest and adenosine stress T1 mapping (ShMOLLI) and late gadolinium enhancement to rule out presence of scar tissue. ΔT1 was determined for the three main vascular territories and compared with [15O]H2O PET-derived regional stress myocardial blood flow (MBF) and myocardial flow reserve (MFR). ΔT1 showed a significant but poor correlation with stress MBF (R2 = 0.04, P = 0.03) and MFR (R2 = 0.07, P = 0.004). Vascular territories with impaired stress MBF (i.e. ≤2.30 mL/min/g) demonstrated attenuated ΔT1 compared with vascular territories with preserved stress MBF (2.9 ± 2.2% vs. 4.1 ± 2.2%, P = 0.008). In contrast, ΔT1 did not differ between vascular territories with impaired (i.e. <2.50) and preserved MFR (3.2 ± 2.6% vs. 4.0 ± 2.1%, P = 0.25). Receiver operating curve analysis of ΔT1 resulted in an area under the curve of 0.66 [95% confidence interval (CI): 0.57-0.75, P = 0.009] for diagnosing impaired stress MBF and 0.62 (95% CI: 0.53-0.71, P = 0.07) for diagnosing impaired MFR., Conclusions: CMR stress T1 mapping has poor agreement with [15O]H2O PET measurements of absolute myocardial perfusion. Stress T1 and ΔT1 are lower in vascular territories with reduced stress MBF but have poor accuracy for detecting impaired myocardial perfusion., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)

Objectives: This study evaluated myocardial viability as well as global and regional functional recovery after successful chronic coronary total occlusion (CTO) percutaneous coronary intervention (PCI) using sequential quantitative cardiac magnetic resonance (CMR) imaging., Background: The patient benefits of CTO PCI are being questioned., Methods: In a single high-volume CTO PCI center patients were prospectively scheduled for CMR at baseline and 3 months after successful CTO PCI between 2013 and 2018. Segmental wall thickening (SWT) and percentage late gadolinium enhancement (LGE) were quantitatively measured per segment. Viability was defined as dysfunctional myocardium (<2.84 mm SWT) with no or limited scar (≤50% LGE)., Results: A total of 132 patients were included. Improvement of left ventricular ejection fraction was modest after CTO PCI (from 48.1 ± 11.8 to 49.5 ± 12.1%, p < 0.01). CTO segments with viability (N = 216, [31%]) demonstrated a significantly higher increase in SWT (0.80 ± 1.39 mm) compared to CTO segments with pre-procedural preserved function (N = 456 [65%], 0.07 ± 1.43 mm, p < 0.01) or extensive scar (LGE >50%, N = 26 [4%], -0.08 ± 1.09 mm, p < 0.01). Patients with ≥2 CTO segments viability showed more SWT increase in the CTO territory compared to patients with 0-1 segment viability (0.49 ± 0.93 vs. 0.12 ± 0.98 mm, p = 0.03)., Conclusions: Detection of dysfunctional myocardial segments without extensive scar (≤50% LGE) as a marker for viability on CMR aids in identifying patients with significant regional functional recovery after CTO PCI., (© 2021 The Authors. Catheterization and Cardiovascular Interventions published by Wiley Periodicals LLC.)

To evaluate the effect of percutaneous coronary intervention (PCI) of coronary chronic total occlusions (CTOs) on left ventricular (LV) strain assessed using cardiac magnetic resonance (CMR) tissue tracking. In 150 patients with a CTO, longitudinal (LS), radial (RS) and circumferential shortening (CS) were determined using CMR tissue tracking before and 3 months after successful PCI. In patients with impaired LV strain at baseline, global LS (10.9 ± 2.4% vs 11.6 ± 2.8%; P = 0.006), CS (11.3 ± 2.9% vs 12.0 ± 3.5%; P = 0.002) and RS (15.8 ± 4.9% vs 17.4 ± 6.6%; P = 0.001) improved after revascularization of the CTO, albeit to a small, clinically irrelevant, extent. Strain improvement was inversely related to the extent of scar, even after correcting for baseline strain (B =  - 0.05; P = 0.008 for GLS, B =  - 0.06; P = 0.016 for GCS, B =  - 0.13; P = 0.017 for GRS). In the vascular territory of the CTO, dysfunctional segments showed minor improvement in both CS (10.8 [6.9 to 13.3] % vs 11.9 [8.1 to 15.0] %; P < 0.001) and RS (14.2 [8.4 to 18.7] % vs 16.0 [9.9 to 21.8] %; P < 0.001) after PCI. Percutaneous revascularization of CTOs does not lead to a clinically relevant improvement of LV function, even in the subgroup of patients and segments most likely to benefit from revascularization (i.e. LV dysfunction at baseline and no or limited myocardial scar)., (© 2021. The Author(s).)

Objectives: Quantitative flow ratio (QFR) computes fractional flow reserve (FFR) based on invasive coronary angiography (ICA). Residual QFR estimates post-percutaneous coronary intervention (PCI) FFR. This study sought to assess the relationship of residual QFR with post-PCI FFR., Methods: Residual QFR analysis, using pre-PCI ICA, was attempted in 159 vessels with post-PCI FFR. QFR lesion location was matched with the PCI location to simulate the performed intervention and allow computation of residual QFR. A post-PCI FFR < 0.90 was used to define a suboptimal PCI result., Results: Residual QFR computation was successful in 128 (81%) vessels. Median residual QFR was higher than post-PCI FFR (0.96 Q1-Q3: 0.91-0.99 vs. 0.91 Q1-Q3: 0.86-0.96, p < 0.001). A significant correlation and agreement were observed between residual QFR and post-PCI FFR ( R  = 0.56 and intraclass correlation coefficient = 0.47, p < 0.001 for both). Following PCI, an FFR < 0.90 was observed in 54 (42%) vessels. Specificity, positive predictive value, sensitivity, and negative predictive value of residual QFR for assessment of the PCI result were 96% (95% confidence interval (CI): 87-99%), 89% (95% CI: 72-96%), 44% (95% CI: 31-59%), and 70% (95% CI: 65-75%), respectively. Residual QFR had an accuracy of 74% (95% CI: 66-82%) and an area under the receiver operating characteristic curve of 0.79 (95% CI: 0.71-0.86)., Conclusions: A significant correlation and agreement between residual QFR and post-PCI FFR were observed. Residual QFR ≥ 0.90 did not necessarily commensurate with a satisfactory PCI (post-PCI FFR ≥ 0.90). In contrast, residual QFR exhibited a high specificity for prediction of a suboptimal PCI result., Competing Interests: Dr. Knaapen has received research grants from HeartFlow. All other authors declare that they have no conflicts of interest., (Copyright © 2021 Pepijn A. van Diemen et al.)

Objectives: This study was designed to assess the prognostic value of pericoronary adipose tissue computed tomography attenuation (PCATa) beyond quantitative coronary computed tomography angiography (CCTA)-derived plaque volume and positron emission tomography (PET) determined ischemia., Background: Inflammation plays a crucial role in atherosclerosis. PCATa has been shown to assess coronary-specific inflammation and is of prognostic value in patients with suspected coronary artery disease (CAD)., Methods: A total of 539 patients who underwent CCTA and [ 15 O]H 2 O PET perfusion imaging because of suspected CAD were included. Imaging assessment included coronary artery calcium score (CACS), presence of obstructive CAD (≥50% stenosis) and high-risk plaques (HRPs), total plaque volume (TPV), calcified/noncalcified plaque volume (CPV/NCPV), PCATa, and myocardial ischemia. The endpoint was a composite of death and nonfatal myocardial infarction. Prognostic thresholds were determined for quantitative CCTA variables., Results: During a median follow-up of 5.0 (interquartile range: 4.7 to 5.0) years, 33 events occurred. CACS >59 Agatston units, obstructive CAD, HRPs, TPV >220 mm 3 , CPV >110 mm 3 , NCPV >85 mm 3 , and myocardial ischemia were associated with shorter time to the endpoint with unadjusted hazard ratios (HRs) of 4.17 (95% confidence interval [CI]: 1.80 to 9.64), 4.88 (95% CI: 1.88 to 12.65), 3.41 (95% CI: 1.72 to 6.75), 7.91 (95% CI: 3.05 to 20.49), 5.82 (95% CI: 2.40 to 14.10), 8.07 (95% CI: 3.33 to 19.55), and 4.25 (95% CI: 1.84 to 9.78), respectively (p < 0.05 for all). Right coronary artery (RCA) PCATa above scanner specific thresholds was associated with worse prognosis (unadjusted HR: 2.84; 95% CI: 1.44 to 5.63; p = 0.003), whereas left anterior descending artery and circumflex artery PCATa were not related to outcome. RCA PCATa above scanner specific thresholds retained is prognostic value adjusted for imaging variables and clinical characteristics associated with the endpoint (adjusted HR: 2.45; 95% CI: 1.23 to 4.93; p = 0.011)., Conclusions: Parameters associated with atherosclerotic burden and ischemia were more strongly associated with outcome than RCA PCATa. Nonetheless, RCA PCATa was of prognostic value beyond clinical characteristics, CACS, obstructive CAD, HRPs, TPV, CPV, NCPV, and ischemia., Competing Interests: Funding Support and Author Disclosures Dr. Knaapen has received research grants from HeartFlow Inc. Dr. Min is employee and has an equity interest in Cleerly, Inc.; and serves on the advisory board of Arineta. Dr. Leipsic has received research grants from GE Healthcare and Edwards Lifesciences; and serves as consultant for HeartFlow Inc. and Circle CVI. Drs. Freiman, Goshen, Heitel, and Langzam are employees of Philips Healthcare. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: The authors sought to evaluate the impact of ischemic burden reduction after chronic total occlusion (CTO) percutaneous coronary intervention (PCI) on long-term prognosis and cardiac symptom relief., Background: The clinical benefit of CTO PCI is questioned., Methods: In a high-volume CTO PCI center, 212 patients prospectively underwent quantitative [ 15 O]H 2 O positron emission tomography perfusion imaging before and three months after successful CTO PCI between 2013-2019. Perfusion defects (PD) (in segments) and hyperemic myocardial blood flow (hMBF) (in ml · min -1 · g -1 ) allocated to CTO areas were related to prognostic outcomes using unadjusted (Kaplan-Meier curves, log-rank test) and risk-adjusted (multivariable Cox regression) analyses. The prognostic endpoint was a composite of all-cause death and nonfatal myocardial infarction., Results: After a median [interquartile range] of 2.8 years [1.8 to 4.3 years], event-free survival was superior in patients with ≥3 versus <3 segment PD reduction (p < 0.01; risk-adjusted p = 0.04; hazard ratio [HR]: 0.34 [95% confidence interval (CI): 0.13 to 0.93]) and with hMBF increase above (Δ≥1.11 ml · min -1 · g -1 ) versus below the population median (p < 0.01; risk-adjusted p < 0.01; HR: 0.16 [95% CI: 0.05 to 0.54]) after CTO PCI. Furthermore, event-free survival was superior in patients without versus any residual PD (p < 0.01; risk-adjusted p = 0.02; HR: 0.22 [95% CI: 0.06 to 0.76]) or with a residual hMBF level >2.3 versus ≤2.3 ml · min -1 · g -1 (p < 0.01; risk-adjusted p = 0.03; HR: 0.25 [95% CI: 0.07 to 0.91]) at follow-up positron emission tomography. Patients with residual hMBF >2.3 ml · min -1 · g -1 were more frequently free of angina and dyspnea on exertion at long-term follow-up (p = 0.04)., Conclusions: Patients with extensive ischemic burden reduction and no residual ischemia after CTO PCI had lower rates of all-cause death and nonfatal myocardial infarction. Long-term cardiac symptom relief was associated with normalization of hMBF levels after CTO PCI., Competing Interests: Funding Support and Author Disclosures The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: Myocardial ischaemic burden (IB) is used for the risk stratification of patients with coronary artery disease (CAD). This study sought to define a prognostic threshold for quantitative [15O]H2O positron emission tomography (PET)-derived IB., Methods and Results: A total of 623 patients with suspected or known CAD who underwent [15O]H2O PET perfusion imaging were included. The endpoint was a composite of death and non-fatal myocardial infarction (MI). A hyperaemic myocardial blood flow (hMBF) and myocardial flow reserve (MFR)-derived IB were determined. During a median follow-up time of 6.7 years, 62 patients experienced an endpoint. A hMBF IB of 24% and MFR IB of 28% were identified as prognostic thresholds. Patients with a high hMBF or MFR IB (above threshold) had worse outcome compared to patients with a low hMBF IB [annualized event rates (AER): 2.8% vs. 0.6%, P < 0.001] or low MFR IB [AER: 2.4% vs. 0.6%, P < 0.001]. Patients with a concordant high IB had the worst outcome (AER: 3.1%), whereas patients with a concordant low or discordant IB result had similar and low AERs of 0.5% and 0.9% (P = 0.953), respectively. Both thresholds were of prognostic value beyond clinical characteristics, however, only the hMBF IB threshold remained predictive when adjusted for clinical characteristics and combined use of the hMBF and MFR thresholds., Conclusion: A hMBF IB ≥24% was a stronger predictor of adverse outcome than an MFR IB ≥28%. Nevertheless, classifying patients according to concordance of IB result allowed for the identification of low- and high-risk patients., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

[Figure: see text].

Objectives: This study aimed to investigate the performance of computed tomography derived fractional flow reserve based interactive planner (FFR CT planner) to predict the physiological benefits of percutaneous coronary intervention (PCI) as defined by invasive post-PCI FFR., Background: Advances in FFR CT technology have enabled the simulation of hyperemic pressure changes after virtual removal of stenoses., Methods: In 56 patients (63 vessels) invasive FFR measurements before and after PCI were obtained and FFR CT was calculated using pre-PCI coronary CT angiography. Subsequently, FFR CT and invasive coronary angiography models were aligned allowing virtual removal of coronary stenoses on pre-PCI FFR CT models in the same locations as PCI was performed. Relationships between invasive FFR and FFR CT , between post-PCI FFR and FFR CT planner, and between delta FFR and delta FFR CT were evaluated., Results: Pre PCI, invasive FFR was 0.65 ± 0.12 and FFR CT was 0.64 ± 0.13 (p = .34) with a mean difference of 0.015 (95% CI: -0.23-0.26). Post-PCI invasive FFR was 0.89 ± 0.07 and FFR CT planner was 0.85 ± 0.07 (p < .001) with a mean difference of 0.040 (95% CI: -0.10-0.18). Delta invasive FFR and delta FFR CT were 0.23 ± 0.12 and 0.21 ± 0.12 (p = .09) with a mean difference of 0.025 (95% CI: -0.20-0.25). Significant correlations were found between pre-PCI FFR and FFR CT (r = 0.53, p < .001), between post-PCI FFR and FFR CT planner (r = 0.41, p = .001), and between delta FFR and delta FFR CT (r = 0.57, p < .001)., Conclusions: The non-invasive FFR CT planner tool demonstrated significant albeit modest agreement with post-PCI FFR and change in FFR values after PCI. The FFR CT planner tool may hold promise for PCI procedural planning; however, improvement in technology is warranted before clinical application., (© 2020 The Authors. Catheterization and Cardiovascular Interventions published by Wiley Periodicals LLC.)

Background and Aims: The value of serial coronary artery calcium (CAC) scores to predict changes in absolute myocardial perfusion and epicardial vasomotor function is poorly documented. This study explored the association between progression of CAC score and changes in absolute myocardial perfusion., Methods: Fifty-three patients (26% female) with de novo single-vessel coronary artery disease underwent [ 15 O]H 2 O positron emission tomography/computed tomography at 1 month (baseline), 1 year, and 3 years after complete revascularization with percutaneous coronary intervention (PCI) to assess CAC scores, hyperemic myocardial blood flow (hMBF), coronary flow reserve (CFR) and cold pressor test MBF (CPT-MBF), within the context of the VANISH trial., Results: Baseline CAC score was 0 in 9%, 0.1-99.9 in 40%, 100-399.9 in 36% and ≥400 in 15% of patients, respectively. Mixed model-analysis allowed for averaging perfusion indices over all time points: hMBF (3.74 ± 0.83; 3.33 ± 0.79; 3.08 ± 0.78 and 2.44 ± 0.74 mL min -1 ·g -1 ) and CFR (3.82 ± 1.12; 3.17 ± 0.80; 3.19 ± 0.81; 2.63 ± 0.92) were lower among higher baseline CAC groups (p < 0.01; p = 0.03). However, no significant interaction was found between baseline CAC groups and time after PCI for all perfusion indices, denoting that evolution of perfusion indices over time was not significantly different between CAC groups. Furthermore, CAC progression was not correlated with evolution of hMBF (r = 0.08, p = 0.57), CFR (r = 0.09, p = 0.53) or CPT-MBF (r = 0.03, p = 0.82) during 3 years of follow-up., Conclusions: Higher baseline CAC was associated with lower hMBF and CFR. However, both baseline CAC and its progression were not associated with evolution of absolute hMBF, CFR and CPT-MBF over time, suggesting that CAC score and progression of CAC are poor indicators of change in absolute myocardial perfusion., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: This study aimed to investigate the diagnostic value of comprehensive on-site coronary computed tomography angiography (CCTA) using stenosis and plaque measures and subtended myocardial mass (V sub ) for fractional flow reserve (FFR) defined hemodynamically obstructive coronary artery disease (CAD). Additionally, the incremental diagnostic value of off-site CT-derived FFR (FFR CT ) was assessed., Methods: Prospectively enrolled patients underwent CCTA followed by invasive FFR interrogation of all major coronary arteries. Vessels with ≥30% stenosis were included for analysis. On-site CCTA assessment included qualitative and quantitative stenosis (visual grading and minimal lumen area, MLA) and plaque measures (characteristics and volumes), and V sub . Diagnostic value of comprehensive on-site CCTA assessment was tested by comparing area under the curves (AUC). In vessels with available FFR CT , the incremental value of off-site FFR CT was tested., Results: In 236 vessels (132 patients), MLA, positive remodeling, non-calcified plaque volume, and V sub were independent on-site CCTA predictors for hemodynamically obstructive CAD (p < 0.05 for all). V sub /MLA 2 outperformed all these on-site CCTA parameters (AUC = 0.85) and V sub was incremental to all other CCTA predictors (p = 0.02). In subgroup analysis (n = 194 vessels), diagnostic performance of FFR CT and V sub /MLA 2 was similar (AUC 0.89 and 0.85 respectively, p = 0.25). Furthermore, diagnostic performance significantly albeit minimally increased when FFR CT was added to on-site CCTA assessment (ΔAUC = 0.03, p = 0.02)., Conclusions: In comprehensive on-site CCTA assessment, V sub /MLA2 demonstrated greatest diagnostic value for hemodynamically obstructive CAD and V sub was incremental to all evaluated CCTA indices. Additionally, adding FFR CT only minimally increased diagnostic performance, demonstrating that on-site CCTA assessment is a reasonable alternative to FFR CT ., Competing Interests: Declaration of competing interest Dr. Min serves as a consultant to Abbott Vascular, serves on the scientific advisory board of Arineta, and has an equity interest in MDDX. Dr. Leipsic has received research grants from GE Healthcare; and serves as a consultant and holds stock options in Circle CVI and HeartFlow. Dr. Taylor has an equity interest in and is an employee of HeartFlow. Dr. Knaapen has received unrestricted research grants from HeartFlow. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2020 [The Author/The Authors]. Published by Elsevier Inc. All rights reserved.)

Objectives: The effect of intraprocedural coronary computed tomography angiography (coronary CTA) guidance on percutaneous coronary intervention (PCI) is unknown. We sought to determine the influence of CTA guidance on procedural strategies and immediate angiographic outcomes of PCI., Methods: Sixty patients were randomized to CTA-guided PCI (29 patients, 36 lesions) or angiography-guided PCI (31 patients, 39 lesions). To enable hands-free manipulation of CTA images by the interventional cardiologist during PCI, we developed an onsite augmented-reality (AR) system comprising a mobile application and AR glass. The primary endpoints were defined as: (1) stent length; and (2) largest stent diameter according to compliance chart. Procedural strategies, two-dimensional (2D) and three-dimensional (3D) quantitative coronary angiography (QCA), and safety outcomes were compared., Results: Whereas CTA guidance resulted in significantly higher frequency of stent postdilation using non-compliant (67% vs 31%; P<.01) and shorter balloons (16.6 ± 5.4 mm vs 20.5 ± 9.4 mm; P=.04) with numerically larger diameter (3.50 ± 0.63 mm vs 3.28 ± 0.45 mm; P=.10), it did not differ from angiography guidance with respect to lesion predilation, stent length, largest stent diameter according to compliance chart, and nominal stent diameter. The results of 2D- and 3D-QCA and safety outcomes were similar between groups. Neither death nor stroke occurred in either group., Conclusions: PCI under intraprocedural CTA guidance is associated with similar stent size selection and more frequent stent postdilation, resulting in comparable immediate angiographic and safety outcomes as compared with PCI under angiographic guidance alone.

Aims: This study sought to determine the prognostic value of combined functional testing using positron emission tomography (PET) perfusion imaging and anatomical testing using coronary computed tomography angiography (CCTA)-derived stenosis severity and plaque morphology in patients with suspected coronary artery disease (CAD)., Methods and Results: In this retrospective study, 539 patients referred for hybrid [15O]H2O PET-CT imaging because of suspected CAD were investigated. PET was used to determine myocardial blood flow (MBF), whereas CCTA images were evaluated for obstructive stenoses and high-risk plaque (HRP) morphology. Patients were followed up for the occurrence of all-cause death and non-fatal myocardial infarction (MI). During a median follow-up of 6.8 (interquartile range 4.8-7.8) years, 42 (7.8%) patients experienced events, including 23 (4.3%) deaths, and 19 (3.5%) MIs. Annualized event rates for normal vs. abnormal results of PET MBF, CCTA-derived stenosis, and HRP morphology were 0.6 vs. 2.1%, 0.4 vs. 2.1%, and 0.8 vs. 2.8%, respectively (P < 0.001 for all). Cox regression analysis demonstrated prognostic values of PET perfusion imaging [hazard ratio (HR) 3.75 (1.84-7.63), P < 0.001], CCTA-derived stenosis [HR 5.61 (2.36-13.34), P < 0.001], and HRPs [HR 3.37 (1.83-6.18), P < 0.001] for the occurrence of death or MI. However, only stenosis severity [HR 3.01 (1.06-8.54), P = 0.039] and HRPs [HR 1.93 (1.00-3.71), P = 0.049] remained independently associated., Conclusion: PET-derived MBF, CCTA-derived stenosis severity, and HRP morphology were univariably associated with death and MI, whereas only stenosis severity and HRP morphology provided independent prognostic value., (© The Author(s) 2020. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Objectives: This study compared the performance of the quantitative flow ratio (QFR) with single-photon emission computed tomography (SPECT) and positron emission tomography (PET) myocardial perfusion imaging (MPI) for the diagnosis of fractional flow reserve (FFR)-defined coronary artery disease (CAD)., Background: QFR estimates FFR solely based on cine contrast images acquired during invasive coronary angiography (ICA). Head-to-head studies comparing QFR with noninvasive MPI are lacking., Methods: A total of 208 (624 vessels) patients underwent technetium- 99 m tetrofosmin SPECT and [ 15 O]H 2 O PET imaging before ICA in conjunction with FFR measurements. ICA was obtained without using a dedicated QFR acquisition protocol, and QFR computation was attempted in all vessels interrogated by FFR (552 vessels)., Results: QFR computation succeeded in 286 (52%) vessels. QFR correlated well with invasive FFR overall (R = 0.79; p < 0.001) and in the subset of vessels with an intermediate (30% to 90%) diameter stenosis (R = 0.76; p < 0.001). Overall, per-vessel analysis demonstrated QFR to exhibit a superior sensitivity (70%) in comparison with SPECT (29%; p < 0.001), whereas it was similar to PET (75%; p = 1.000). Specificity of QFR (93%) was higher than PET (79%; p < 0.001) and not different from SPECT (96%; p = 1.000). As such, the accuracy of QFR (88%) was superior to both SPECT (82%; p = 0.010) and PET (78%; p = 0.004). Lastly, the area under the receiver operating characteristics curve of QFR, in the overall sample (0.94) and among vessels with an intermediate lesion (0.90) was higher than SPECT (0.63 and 0.61; p < 0.001 for both) and PET (0.82; p < 0.001 and 0.77; p = 0.002), respectively., Conclusions: In this head-to-head comparative study, QFR exhibited a higher diagnostic value for detecting FFR-defined significant CAD compared with perfusion imaging by SPECT or PET., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: This study aimed to evaluate associations between coronary collaterals and myocardial viability as assessed by quantitative cardiac magnetic resonance (CMR) imaging in patients with a chronic coronary total occlusion (CTO)., Methods and Results: A total of 218 patients with a CTO who underwent CMR between 2013 and 2018 were included. A concomitant collateral connection (CC) score 2 and Rentrop grade 3 defined well-developed collaterals in 146 (67%) patients, whereas lower CC scores or Rentrop grades characterised poorly developed collaterals. Dysfunctional myocardium (<3 mm segmental wall thickening [SWT]) and ≤50% late gadolinium enhancement (LGE) defined viability. Extensive scar (LGE >50%) was observed in only 5% of CTO segments. In the CTO territory, SWT was greater (3.72±1.51 vs 3.05±1.60 mm, p<0.01) and the extent of scar was less (7.0 [0.1-16.7] vs 13.1% [2.8-22.2], p=0.048) in patients having well-developed versus poorly developed collaterals. Viability was more prevalent in CTO segments among patients with poorly developed versus well-developed collaterals (44% vs 30% of segments, p<0.01), predominantly due to a higher prevalence of dysfunctional myocardium (51% vs 34% of segments, p<0.01) in the poorly developed collateral group., Conclusions: The infarcted area in myocardium subtended by a CTO is generally limited. Well-developed collaterals are associated with less myocardial scar and enhanced preserved function. However, viability was regularly present in patients with poorly developed collaterals.

Aims: The aim of this study was to explore the relationships between ischaemic burden and changes in absolute myocardial perfusion following chronic coronary total occlusion (CTO) percutaneous coronary intervention (PCI)., Methods and Results: A total of 193 consecutive patients underwent [15O]H2O positron emission tomography prior to and three months after successful CTO PCI. Change in perfusion defect size, quantitative hyperaemic myocardial blood flow (MBF) and coronary flow reserve (CFR) within the CTO area were compared among patients with limited (0-1 segment, N=15), moderate (2-3 segments, N=61) and large (≥4 segments, N=117) perfusion defects. Median reductions in defect size were 1 [0-1], 2 [1-3], and 4 [2-5] segments in patients with a limited, moderate and large defect (all comparisons p<0.01). Hyperaemic MBF and CFR improved significantly regardless of baseline defect size (overall between groups p=0.45 and p=0.55). After stratification of patients to a low, intermediate or high tertile according to baseline hyperaemic MBF or CFR levels, changes in hyperaemic MBF and CFR after CTO PCI were comparable between tertiles (overall p=0.75 and p=0.79)., Conclusions: Major reductions in ischaemic burden can be achieved following CTO PCI, with more defect size reduction in patients with a larger perfusion defect, whereas hyperaemic MBF and CFR improve significantly irrespective of their baseline values or perfusion defect size.

Determining the anatomic severity and extent of coronary artery disease (CAD) by means of coronary computed tomography angiography (CCTA) and its effect on perfusion using myocardial perfusion imaging (MPI) form the pillars of the non-invasive imaging assessment of CAD. This review will 1) focus on CCTA and [ 15 O]H 2 O positron emission tomography MPI as stand-alone imaging modalities and their combined use for detecting CAD, 2) highlight some of the lessons learned from the PACIFIC trial (Comparison of Coronary CT Angiography, SPECT, PET, and Hybrid Imaging for Diagnosis of Ischemic Heart Disease Determined by Fractional Flow Reserve (FFR) (NCT01521468)), and 3) discuss the use of [ 15 O]H 2 O PET MPI in the clinical work-up of patients with a chronic coronary total occlusion (CTO).

Aims: To evaluate the prognostic value of global and regional quantitative [15O]H2O positron emission tomography (PET) perfusion., Methods and Results: In this retrospective study, 648 patients with suspected or known coronary artery disease (CAD) who underwent [15O]H2O PET were followed for the occurrence of death and myocardial infarction (MI). Global and regional hyperaemic myocardial blood flow (hMBF) and coronary flow reserve (CFR) were obtained from [15O]H2O PET. During median follow-up of 6.9 (5.0-7.9) years, 64 (9.9%) patients experienced the composite of death (36-5.6%) and MI (28-4.3%). Impaired global hMBF (<2.65 mL/min/g) and CFR (<2.88) were both significant prognostic factors for death/MI after adjusting for clinical characteristics (both P < 0.001). However, after adjusting for clinical parameters and the combined use of hMBF and CFR, only hMBF remained an independent prognostic factor (P = 0.04). For regional perfusion, both impaired hMBF (<2.10 mL/min/g) and CFR (<2.07) demonstrated prognostic value for events (both P < 0.001). Similarly, after adjusting for clinical characteristics and combined use of hMBF and CFR, only hMBF had independent prognostic value (P = 0.04). The combination of global and regional perfusion did not improve prognostic performance over either global (P = 0.55) or regional perfusion (P = 0.37) alone., Conclusion: Global and regional hMBF and CFR were all prognostic factors for death and MI. However, for both global and regional perfusion, hMBF remained the only independent prognostic factor after adjusting for the combined use of hMBF and CFR. Additionally, integrating global and regional perfusion did not increase prognostic performance compared to either regional or global perfusion alone., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Purpose: To compare cardiac magnetic resonance imaging (CMR) with [ 15 O]H 2 O positron emission tomography (PET) for quantification of absolute myocardial blood flow (MBF) and myocardial flow reserve (MFR) in patients with coronary artery disease (CAD)., Methods: Fifty-nine patients with stable CAD underwent CMR and [ 15 O]H 2 O PET. The CMR imaging protocol included late gadolinium enhancement to rule out presence of scar tissue and perfusion imaging using a dual sequence, single bolus technique. Absolute MBF was determined for the three main vascular territories at rest and during vasodilator stress., Results: CMR measurements of regional stress MBF and MFR showed only moderate correlation to those obtained using PET (r = 0.39; P < 0.001 for stress MBF and r = 0.36; P < 0.001 for MFR). Bland-Altman analysis revealed a significant bias of 0.2 ± 1.0 mL/min/g for stress MBF and - 0.5 ± 1.2 for MFR. CMR-derived stress MBF and MFR demonstrated area under the curves of respectively 0.72 (95% CI: 0.65 to 0.79) and 0.76 (95% CI: 0.69 to 0.83) and had optimal cutoff values of 2.35 mL/min/g and 2.25 for detecting abnormal myocardial perfusion, defined as [ 15 O]H 2 O PET-derived stress MBF ≤ 2.3 mL/min/g and MFR ≤ 2.5. Using these cutoff values, CMR and PET were concordant in 137 (77%) vascular territories for stress MBF and 135 (80%) vascular territories for MFR., Conclusion: CMR measurements of stress MBF and MFR showed modest agreement to those obtained with [ 15 O]H 2 O PET. Nevertheless, stress MBF and MFR were concordant between CMR and [ 15 O]H 2 O PET in 77% and 80% of vascular territories, respectively.

Introduction: Visually estimated angiographic V-RESOLVE score was developed as a simple and accurate prediction tool for side branch (SB) occlusion in patients undergoing coronary bifurcation intervention. Data on the use of coronary computed tomography angiography (coronary CTA) for guiding percutaneous coronary intervention in bifurcation lesions is scarce., Objectives: We aimed to validate the ability of quantitative CTA-derived RESOLVE score for predicting SB occlusion in coronary bifurcation intervention and to compare its predictive value with that of the angiography-based V-RESOLVE score., Methods: We included 363 patients with 400 bifurcation lesions. Angiographic V-RESOLVE score and CTA-derived RESOLVE score were calculated utilizing the weights from the QCA-based RESOLVE score. The scoring systems were divided into quartiles, and classified as the non-high-risk group and the high-risk group. Accuracy was assessed using areas under the receiver-operator characteristic curve (AUC). SB occlusion was defined as any decrease in Thrombolysis in Myocardial Infarction flow grade (including the absence of flow) in the SB after main vessel stenting., Results: In total, 28 SB occlusions (7%) occurred. CTA-derived RESOLVE and V-RESOLVE scores achieved comparable predictive accuracy (0.709 vs. 0.752, respectively, p = 0.531) for predicting SB occlusion, and the analysis of AUC for each constituent element of the scores did not show any significant difference between CTA and visual angiography. The total net reclassification index was -18.6% (p = 0.194), and there were no significant differences in the rates of SB occlusion in the non-high-risk group (4.9% vs. 3.8%, p = 0.510) and the high-risk group (13.8% vs. 18.6%, p = 0.384) between CTA-derived RESOLVE and V-RESOLVE scores., Conclusions: The quantitative CTA-derived RESOLVE score is an accurate and reliable alternative to the visually estimated angiographic V-RESOLVE score for prediction of SB occlusion in coronary bifurcation intervention., Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03709836., Competing Interests: Declaration of competing interest Authors have no conflict of interest to declare., (Copyright © 2020 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Objectives: This study sought to determine the agreement between cardiac magnetic resonance (CMR) imaging and invasive measurements of fractional flow reserve (FFR) in the evaluation of nonculprit lesions after ST-segment elevation myocardial infarction (STEMI). In addition, we investigated whether fully quantitative analysis of myocardial perfusion is superior to semiquantitative and visual analysis., Background: The agreement between CMR and FFR in the evaluation of nonculprit lesions in patients with STEMI with multivessel disease is unknown., Methods: Seventy-seven patients with STEMI with at least 1 intermediate (diameter stenosis 50% to 90%) nonculprit lesion underwent CMR and invasive coronary angiography in conjunction with FFR measurements at 1 month after primary intervention. The imaging protocol included stress and rest perfusion, cine imaging, and late gadolinium enhancement. Fully quantitative, semiquantitative, and visual analysis of myocardial perfusion were compared against a reference of FFR. Hemodynamically obstructive was defined as FFR ≤0.80., Results: Hemodynamically obstructive nonculprit lesions were present in 31 (40%) patients. Visual analysis displayed an area under the curve (AUC) of 0.74 (95% confidence interval [CI]: 0.62 to 0.83), with a sensitivity of 73% and a specificity of 70%. For semiquantitative analysis, the relative upslope of the stress signal intensity time curve and the relative upslope derived myocardial flow reserve had respective AUCs of 0.66 (95% CI: 0.54 to 0.77) and 0.71 (95% CI: 0.59 to 0.81). Fully quantitative analysis did not augment diagnostic performance (all p > 0.05). Stress myocardial blood flow displayed an AUC of 0.76 (95% CI: 0.64 to 0.85), with a sensitivity of 69% and a specificity of 77%. Similarly, MFR displayed an AUC of 0.82 (95% CI: 0.71 to 0.90), with a sensitivity of 82% and a specificity of 71%., Conclusions: CMR and FFR have moderate-good agreement in the evaluation of nonculprit lesions in patients with STEMI with multivessel disease. Fully quantitative, semiquantitative, and visual analysis yield similar diagnostic performance., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Scan quality can have a significant effect on the diagnostic performance of non-invasive imaging techniques. However, the extent of its influence has scarcely been investigated in a head-to-head manner., Methods: Two-hundred and eight patients underwent CCTA, SPECT, and PET prior to invasive fractional flow reserve measurements. Scan quality was classified as either good, moderate, or poor., Results: Distribution of good, moderate, and poor quality scans was; CCTA; 66%, 22%, 13%; SPECT; 52%, 38%, 9%; PET; 86%, 13%, 1%. Good quality CCTA scans possessed a higher specificity (75% vs. 31%, p = 0.001), positive predictive value (PPV, 71% vs. 51%, p = 0.050), and accuracy (80% vs. 60%, p = 0.009) compared to moderate quality scans, while sensitivity (94%) and negative predictive value (NPV, 88%) were similar to moderate and poor quality scans. Sensitivity (76%), NPV (84%), and accuracy (85%) of good quality SPECT scans was superior to those of moderate (41% p = 0.001, 56% p = 0.010, 70% p = 0.010) and poor quality (30% p = 0.003, 65% p = 0.069, 63% p = 0.038). Specificity (92%) and PPV (87%) of good quality SPECT scans did not differ from scans of diminished quality. Good quality PET scans exhibited high sensitivity (84%), specificity (86%), NPV (88%), PPV (81%) and accuracy (85%), which was comparable to scans of lesser quality. Good quality CCTA, SPECT, and PET scans demonstrated a similar diagnostic accuracy (p = 0.247)., Conclusion: Diagnostic performance of CCTA, and SPECT is hampered by scan quality, while the diagnostic value of PET is not affected. Good quality CCTA, SPECT, and PET scans possess a high diagnostic accuracy., (Copyright © 2020 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Objectives: This study sought to assess the presence and morphological features of coronary plaques on optical coherence tomography (OCT) as the causes of myocardial infarction with nonobstructive coronary arteries (MINOCA)., Background: Although coronary atherosclerosis has been postulated as a potential mechanism of MINOCA, the interaction between disrupted coronary plaques and myocardial injury remains unknown., Methods: In a prospective study, consecutive patients with MI but without significant coronary stenosis (≥50%) at angiography underwent OCT and cardiac magnetic resonance (CMR) with late gadolinium-enhancement (LGE). The infarct-related artery (IRA) was identified by localization of ischemic-type LGE., Results: Thirty-eight MINOCA patients (mean age 62 ± 13 years, 55% female, 39% with ST-segment elevation) were enrolled. Maximal diameter stenosis was 35% by angiography, and 5 patients (13%) had normal angiogram results. Plaque disruption and coronary thrombus were observed in 9 patients (24%) and 7 patients (18%), respectively. Sixteen of 31 patients (52%) undergoing CMR showed LGE. Ischemic-type LGE was present in 7 patients (23%) and was more common in patients with than without plaque disruption (50% vs. 13%, respectively; p = 0.053) and coronary thrombus (67% vs. 12%, respectively; p = 0.014). In the per-lesion analysis, the IRA showed significantly more plaque disruption (40% vs. 6%; p = 0.02), thrombus (50% vs. 4%; p = 0.014), and thin-cap fibroatheroma (70% vs. 30%; p = 0.03) than the non-IRA., Conclusions: Plaque disruption and thrombus are not uncommon in MI without obstructive coronary stenoses at angiography and may be associated with the presence and location of ischemic-type myocardial injury on CMR. OCT may be valuable in identifying atherosclerotic etiology in individuals with MINOCA. (Optical Coherence Tomography in Patients With Acute Myocardial Infarction and Nonobstructive Coronary Artery Disease [SOFT-MI]; NCT02783963)., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Multiple crossing techniques in chronic total occlusion (CTO) percutaneous coronary intervention have been developed. This study compared recovery of quantitative myocardial blood flow (MBF) after different CTO percutaneous coronary intervention techniques., Methods: Consecutive patients with [ 15 O]H 2 O positron emission tomography perfusion imaging before and 3 months after successful CTO percutaneous coronary intervention between 2013 and 2018 were included. Changes in hyperemic MBF, coronary flow reserve, and perfusion defect size were compared between antegrade wire escalation, retrograde wire escalation, antegrade dissection and reentry (ADR), and retrograde dissection and reentry., Results: One hundred ninety-three patients were treated with antegrade wire escalation (N=90), retrograde wire escalation (N=24), ADR (N=35), and retrograde dissection and reentry (N=44). Increase in hyperemic MBF (1.19±0.77, 0.94±0.65, 1.09±0.63, and 1.02±0.75 mL·min -1 ·g -1 , respectively; P =0.40) and coronary flow reserve (1.34±1.08, 1.14±1.09, 1.31±0.96, and 1.24±0.99, respectively; P =0.84) and decrease in defect size (3.2±2.1, 3.0±2.2, 2.7±2.1, and 2.9±1.9 segments, respectively; P =0.77) were comparable between the 4 approaches. In addition, recovery of hyperemic MBF was less pronounced after subintimal crossing with knuckle-wire-technique compared with CrossBoss in controlled ADR and retrograde dissection and reentry (0.93±0.69 versus 1.54±0.65 mL·min -1 ·g -1 , P =0.02), and less after reentry using subintimal tracking and reentry in ADR compared with controlled ADR (Stingray) or limited antegrade subintimal tracking (0.60±0.53 versus 1.18±0.54 [ P =0.04] and versus 1.49±0.57 mL·min -1 ·g -1 , [ P <0.01])., Conclusions: Recovery of hyperemic MBF, coronary flow reserve, and perfusion defect size after CTO percutaneous coronary intervention was comparable between different approaches. Although sometimes necessary to cross a complex CTO lesion, subintimal knuckle wiring and subintimal tracking and reentry resulted in less hyperemic MBF improvement compared with other subintimal crossing and reentry techniques.

Scan quality directly impacts the diagnostic performance of non-invasive imaging modalities as reported in a substudy of the PACIFC-trial: "Impact of Scan Quality on the Diagnostic Performance of CCTA, SPECT, and PET for Diagnosing Myocardial Ischemia Defined by Fractional Flow Reserve" [1]. This Data-in-Brief paper supplements the hereinabove mentioned article by presenting the diagnostic performance of CCTA, SPECT, and PET on a per vessel level for the detection of hemodynamic significant coronary artery disease (CAD) when stratified according to scan quality and vascular territory., (© 2019 The Author(s).)

Aims: Continuous thermodilution is a novel technique to quantify absolute coronary flow and microvascular resistance (MVR). Notably, intracoronary infusion of saline elicits maximal hyperaemia, obviating the need for adenosine. The primary aim of this study was to validate continuous thermodilution in humans by comparing invasive measurements to [15O]H2O positron emission tomography (PET). As a secondary goal, absolute flow and MVR were compared between invasive measurements obtained with and without adenosine., Methods and Results: Twenty-five patients underwent coronary computed tomography angiography (CCTA), [15O]H2O PET, and invasive assessment. Absolute coronary flow and MVR were measured in the left anterior descending and left circumflex artery using a dedicated infusion catheter and a temperature/pressure sensor-tipped guidewire. Invasive measurements were performed with and without adenosine. In order to compare invasive flow measurements with PET perfusion, subtending myocardial mass of the investigated vessels was derived from CCTA using the Voronoi algorithm. Invasive and non-invasive measurements of adenosine-induced hyperaemic flow and MVR showed strong correlation (r = 0.91; P < 0.001 for flow and r = 0.85; P < 0.001 for MVR) and good agreement [intraclass correlation coefficient (ICC) = 0.90; P < 0.001 for flow and ICC = 0.79; P < 0.001 for MVR]. Absolute flow and MVR also correlated well between measurements with and without adenosine (r = 0.97; P < 0.001 for flow and r = 0.98; P < 0.001 for MVR) and showed good agreement (ICC = 0.96; P < 0.001 for flow and ICC = 0.98; P < 0.001 for MVR)., Conclusions: Continuous thermodilution is an accurate method to measure absolute coronary flow and MVR, which is evidenced by strong agreement with [15O]H2O PET derived flow and resistance. Absolute flow and MVR correlate highly between invasive measurements obtained with and without adenosine, which confirms that intracoronary infusion of room temperature saline elicits steady-state maximal hyperaemia., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Next to myocardial perfusion, single-photon emission computed tomography (SPECT) also allows for the assessment of nonperfusion parameters such as transient ischemic dilatation (TID) and a reduction of ejection fraction (EF) with stress imaging. This study aimed to evaluate the diagnostic value of TID and EF reserve for the detection of significant multivessel coronary artery disease (CAD). A total of 206 patients with suspected stable CAD prospectively underwent gated stress-rest Tc-tetrofosmin SPECT and invasive coronary angiography with routine fractional flow reserve (FFR) measurements, irrespective of imaging results. Left ventricular volumes, TID, and EF reserve were assessed and compared with FFR-defined severity of CAD. According to FFR, 92 (45%) patients had significant CAD, whereas 25 (12%) showed 2-vessel disease (VD) and 22 (11%) showed 3-VD. With an increasing extent of CAD, TID values and EF reserve did not change significantly (P=0.07 and 0.42 for trend, respectively). Conversely, absolute left ventricular volumes and EF differed significantly among groups of CAD severity (P<0.01 for all trends). SPECT-derived TID and EF reserve did not differ between patients with high-risk CAD (3-VD) and low risk or no significant CAD. Therefore, the present results advocate exerting caution when using these ancillary findings in clinical practice.

Background: A diminished coronary lumen volume to left ventricle mass ratio (V/M) derived from coronary computed tomography angiography (CCTA) has been proposed as factor contributing to impaired myocardial blood flow (MBF) even in the absence of obstructive disease on invasive coronary angiography (ICA)., Methods: Patients underwent CCTA, and positron emission tomography (PET) prior to ICA. Matched global V/M, global, and vessel specific hyperaemic MBF (hMBF), coronary flow reserve (CFR), and, FFR were available for 431 vessels in 152 patients. The median V/M (20.71 mm 3 /g) was used to divide the population into patients with either a low V/M or a high V/M., Results: Overall, a higher percentage of vessels with an abnormal hMBF and FFR (34% vs. 19%, p = 0.009 and 20% vs. 9%, p = 0.004), as well as a lower FFR (0.93 [interquartile range: 0.85-0.97] vs. 0.95 [0.89-0.98], p = 0.016) values were observed in the low V/M group. V/M was weakly associated with vessel specific hMBF (R = 0.148, p = 0.027), and FFR (R = 0.156, p < 0.001). Among vessels with non-obstructive CAD on ICA (361 vessels), no association between V/M and vessel specific hMBF nor CFR was noted. However, in the absence of obstructive CAD, V/M was associated with (R = 0.081, p = 0.027), and independently predictive for FFR (p = 0.047)., Conclusion: Overall, an abnormal vessel specific hMBF and FFR were more prevalent in patients with a low V/M compared to those with a high V/M. Furthermore, V/M was weakly associated with vessel specific hMBF and FFR. In the absence of obstructive CAD on ICA, V/M was weakly associated with notwithstanding independently predictive for FFR., (Copyright © 2019 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Chronic coronary total occlusions (CTO) are diagnosed in up to 20% of patients with coronary artery disease and have a detrimental effect on patients' quality of life and long-term prognosis. The exponential developments in CTO percutaneous coronary intervention (PCI) equipment, recanalization techniques, and operator expertise have been merged into the hybrid approach that represents a percutaneous revascularization algorithm for treating CTOs and has led to technical success over 90% at experienced centers. Therefore, patient selection for CTO PCI should be focused on anticipated patient benefit in terms of health status and long-term prognosis rather than coronary anatomic complexity. TABLE OF CONTENTS: This review will provide an overview of the clinical presentation and characteristics of patients with a CTO and will discuss the essential needs toward judicious patient selection for percutaneous CTO revascularization according to contemporary knowledge. Furthermore, the current high standard revascularization techniques in dedicated CTO PCI will be discussed., (Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objectives: The randomized clinical VANISH (Impact of Vascular Reparative Therapy on Vasomotor Function and Myocardial Perfusion: A Randomized [ 15 O]H 2 O PET/CT Study) trial was conducted to assess quantitative myocardial blood flow (MBF) during resting, hyperemia, and cold pressor testing (CPT) with positron emission tomographic perfusion imaging after the implantation of a bioresorbable everolimus-eluting scaffold compared with a drug-eluting stent., Background: Long-term resorption of the bioresorbable everolimus-eluting scaffold reinstates normal vessel geometry, allowing natural regeneration of the newly formed endothelium with revival of vasomotor function., Methods: Sixty patients (18 to 65 years of age) with single-vessel disease and type A or B1 lesions were randomized in a 1-to-1 fashion. Approximately 1 month, 1 year, and 3 years after device implantation, patients underwent [ 15 O]H 2 O cardiac positron emission tomography. The primary endpoint was the interaction of device type and evolution over time of hyperemic MBF, coronary flow reserve, or CPT reserve. At 3-year follow-up, control invasive coronary angiography with optical coherence tomography was performed., Results: Fifty-nine (98%), 56 (93%), and 51 (85%) patients successfully completed 1-month, 1-year, and 3-year follow-up positron emission tomography, respectively, and no culprit vessel events were registered during follow-up time. The primary study endpoint (i.e., interaction between device type and time) was nonsignificant for hyperemic MBF, CPT reserve, and coronary flow reserve (p > 0.05 for all). In all patients, hyperemic MBF decreased from 1 to 3 years (p = 0.02), while coronary flow reserve was lower at 3-year follow-up compared with 1-month and 1-year follow-up (p = 0.03 for both). After 3 years, percentage area stenosis measured with optical coherence tomography was higher within the bioresorbable everolimus-eluting scaffold compared with the drug-eluting stent (p = 0.03)., Conclusions: The hypothesized beneficial effects of scaffold resorption did not translate to improved MBF during maximal hyperemia or endothelium-dependent vasodilation by CPT., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: Despite high variability in coronary anatomy, quantitative positron emission tomography (PET) perfusion in coronary territories is traditionally calculated according to the American Heart Association (AHA) 17-segments model. This study aimed to assess the impact of individualized segmentation of myocardial segments on the diagnostic accuracy of hyperaemic myocardial blood flow (MBF) values for haemodynamically significant coronary artery disease (CAD)., Methods and Results: Patients with suspected CAD (n = 204) underwent coronary computed tomography angiography (CCTA) and [15O]H2O PET followed by invasive coronary angiography with fractional flow reserve assessment of all major coronary arteries. Hyperaemic MBF per vascular territory was calculated using both standard segmentation according to the AHA model and individualized segmentation, in which CCTA was used to assign coronary arteries to PET perfusion territories. In 122 (59.8%) patients, one or more segments were redistributed after individualized segmentation. No differences in mean MBF values were seen between segmentation methods, except for a minor difference in hyperaemic MBF in the LCX territory (P = 0.001). These minor changes resulted in discordant PET-defined haemodynamically significant CAD between the two methods in only 5 (0.8%) vessels. The diagnostic value for detecting haemodynamically significant CAD did not differ between individualized and standard segmentation, with area under the curves of 0.79 and 0.78, respectively (P = 0.34)., Conclusions: Individualized segmentation using CCTA-derived coronary anatomy led to redistribution of standard myocardial segments in 60% of patients. However, this had little impact on [15O]H2O PET MBF values and diagnostic value for detecting haemodynamically significant CAD did not change. Therefore, clinical impact of individualized segmentation seems limited., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.)

Background: The benefits of chronic coronary total occlusion (CTO) percutaneous coronary intervention (PCI) are being questioned. The aim of this study was to assess the effects of CTO PCI on absolute myocardial perfusion, as compared with PCI of hemodynamically significant non-CTO lesions., Methods: Consecutive patients with a preserved left ventricular ejection fraction (≥50%) and a CTO or non-CTO lesion, in whom [ 15 O]H 2 O positron emission tomography was performed prior and after successful PCI, were included. Change in quantitative (hyperemic) myocardial blood flow (MBF), coronary flow reserve (CFR) and perfusion defect size (in myocardial segments) were compared between CTOs and non-CTO lesions., Results: In total 92 patients with a CTO and 31 patients with a non-CTO lesion were included. CTOs induced larger perfusion defect sizes (4.51 ± 1.69 vs. 3.23 ± 2.38 segments, P < 0.01) with lower hyperemic MBF (1.30 ± 0.37 vs. 1.58 ± 0.62 mL·min -1 ·g -1 , P < 0.01) and similarly impaired CFR (1.66 ± 0.75 vs. 1.89 ± 0.77, P = 0.17) compared with non-CTO lesions. After PCI both hyperemic MBF and CFR increased similarly between groups (P = 0.57 and 0.35) to normal ranges with higher hyperemic MBF values in non-CTO compared with CTO (2.89 ± 0.94 vs. 2.48 ± 0.73 mL·min -1 ·g -1 , P = 0.03). Perfusion defect sizes decreased similarly after CTO PCI and non-CTO PCI (P = 0.14), leading to small residual defect sizes in both groups (1.15 ± 1.44 vs. 0.61 ± 1.45 segments, P = 0.054)., Conclusions: Myocardial perfusion findings are slightly more hampered in patients with a CTO before and after PCI. Percutaneous revascularization of CTOs, however, improves absolute myocardial perfusion similarly to PCI of hemodynamically significant non-CTO lesions, leading to satisfying results., (© 2018 The Authors. Catheterization and Cardiovascular Interventions published by Wiley Periodicals, Inc.)

Aim: Hyperphosphataemia is associated with increased mortality and morbidity in end stage renal disease. Despite phosphate binder therapy, a large proportion of patients do not reach the treatment target. In five contemporary binders we explored the influence of pH and phosphate concentration on phosphate binding. This interaction could be of relevance in clinical practice., Methods: Phosphate binding was quantified in vitro in 25 mL of purified water containing phosphate concentrations of 10, 15 and 20 mM and baseline pH values of 3.0 or 6.0, with a binder over 6 h. Lanthanum carbonate, calcium acetate/magnesium carbonate, sevelamer carbonate, calcium carbonate and sucroferric oxyhydroxide, 67 mg of each, were used. The experiments were performed in duplicate. The primary outcome was the difference in the amount of bound phosphate for each binder after 6 h in solutions at two different pH values. Secondary outcomes were the influence of phosphate concentration on phosphate binding, next to binding patterns and phosphate binder saturation., Results and Conclusion: In this specific in vitro setting, lanthanum carbonate, sevelamer carbonate, calcium carbonate and sucroferric oxyhydroxide bound more phosphate in the solution with baseline pH of 3.0. Differences however were small except for lanthanum carbonate. Calcium acetate/magnesium carbonate was most effective in a solution with baseline pH of 6.0. All phosphate binders bound more phosphate in solutions with higher concentrations of phosphate. Sevelamer carbonate, calcium acetate/magnesium carbonate and sucroferric oxyhydroxide bound most phosphate in the first hour and reached maximum binding capacity in less than 6 h., (© 2018 The Authors Nephrology published by John Wiley & Sons Australia, Ltd on behalf of Asian Pacific Society of Nephrology.)

Background: Fractional flow reserve (FFR) computation from coronary computed tomography angiography (CTA) datasets (FFR CT ) has emerged as a promising noninvasive test to assess hemodynamic severity of coronary artery disease (CAD), but has not yet been compared with traditional functional imaging., Objectives: The purpose of this study was to evaluate the diagnostic performance of FFR CT and compare it with coronary CTA, single-photon emission computed tomography (SPECT), and positron emission tomography (PET) for ischemia diagnosis., Methods: This subanalysis involved 208 prospectively included patients with suspected stable CAD, who underwent 256-slice coronary CTA, 99mTc-tetrofosmin SPECT, [ 15 O]H 2 O PET, and routine 3-vessel invasive FFR measurements. FFR CT values were retrospectively derived from the coronary CTA images. Images from each modality were interpreted by core laboratories, and their diagnostic performances were compared using invasively measured FFR ≤0.80 as the reference standard., Results: In total, 505 of 612 (83%) vessels could be evaluated with FFR CT . FFR CT showed a diagnostic accuracy, sensitivity, and specificity of 87%, 90%, and 86% on a per-vessel basis and 78%, 96%, and 63% on a per-patient basis, respectively. Area under the receiver-operating characteristic curve (AUC) for identification of ischemia-causing lesions was significantly greater for FFR CT (0.94 and 0.92) in comparison with coronary CTA (0.83 and 0.81; p < 0.01 for both) and SPECT (0.70 and 0.75; p < 0.01 for both), on a per-vessel and -patient level, respectively. FFR CT also outperformed PET on a per-vessel basis (AUC 0.87; p < 0.01), but not on a per-patient basis (AUC 0.91; p = 0.56). In the intention-to-diagnose analysis, PET showed the highest per-patient and -vessel AUC followed by FFR CT (0.86 vs. 0.83; p = 0.157; and 0.90 vs. 0.79; p = 0.005, respectively)., Conclusions: In this study, FFR CT showed higher diagnostic performance than standard coronary CTA, SPECT, and PET for vessel-specific ischemia, provided coronary CTA images were evaluable by FFR CT , whereas PET had a favorable performance in per-patient and intention-to-diagnose analysis. Still, in patients in whom 3-vessel FFR CT could be analyzed, FFR CT holds clinical potential to provide anatomic and hemodynamic significance of coronary lesions., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)