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Background: Two invasive methods are available to estimate microvascular resistance: bolus and continuous thermodilution. Comparative studies have revealed a lack of concordance between measurements of microvascular resistance obtained through these techniques., Aims: This study aimed to examine the influence of vessel volume on bolus thermodilution measurements., Methods: We prospectively included patients with angina with non-obstructive coronary arteries (ANOCA) undergoing bolus and continuous thermodilution assessments. All patients underwent coronary CT angiography to extract vessel volume. Coronary microvascular dysfunction was defined as coronary flow reserve (CFR) < 2.0. Measurements of absolute microvascular resistance (in Woods units) and index of microvascular resistance (IMR) were compared before and after volumetric adjustment., Results: Overall, 94 patients with ANOCA were included in this study. The mean age was 64.7 ± 10.8 years, 48% were female, and 19% had diabetes. The prevalence of CMD was 16% based on bolus thermodilution, while continuous thermodilution yielded a prevalence of 27% (Cohen's Kappa 0.44, 95% CI 0.23-0.65). There was no correlation in microvascular resistance between techniques (r = 0.17, 95% CI -0.04 to 0.36, p = 0.104). The adjustment of IMR by vessel volume significantly increased the agreement with absolute microvascular resistance derived from continuous thermodilution (r = 0.48, 95% CI 0.31-0.63, p < 0.001)., Conclusions: In patients with ANOCA, invasive methods based on coronary thermodilution yielded conflicting results for the assessment of CMD. Adjusting IMR with vessel volume improved the agreement with continuous thermodilution for the assessment of microvascular resistance. These findings strongly suggest the importance of considering vessel volume when interpreting bolus thermodilution assessment., (© 2024 Wiley Periodicals LLC.)

Background: Fractional flow reserve (FFR) measured after percutaneous coronary intervention (PCI) carries prognostic information. Yet, myocardial mass subtended by a stenosis influences FFR. We hypothesized that a smaller coronary lumen volume and a large myocardial mass might be associated with lower post-PCI FFR., Aim: We sought to assess the relationship between vessel volume, myocardial mass, and post-PCI FFR., Methods: This was a subanalysis with an international prospective study of patients with significant lesions (FFR ≤ 0.80) undergoing PCI. Territory-specific myocardial mass was calculated from coronary computed tomography angiography (CCTA) using the Voronoi's algorithm. Vessel volume was extracted from quantitative CCTA analysis. Resting full-cycle ratio (RFR) and FFR were measured before and after PCI. We assessed the association between coronary lumen volume (V) and its related myocardial mass (M), and the percent of total myocardial mass (%M) with post-PCI FFR., Results: We studied 120 patients (123 vessels: 94 left anterior descending arteries, 13 left Circumflex arteries, 16 right coronary arteries). Mean vessel-specific mass was 61 ± 23.1 g (%M 39.6 ± 11.7%). The mean post-PCI FFR was 0.88 ± 0.06 FFR units. Post-PCI FFR values were lower in vessels subtending higher mass (0.87 ± 0.05 vs. 0.89 ± 0.07, p = 0.047), and with lower V/M ratio (0.87 ± 0.06 vs. 0.89 ± 0.07, p = 0.02). V/M ratio correlated significantly with post-PCI RFR and FFR (RFR r = 0.37, 95% CI: 0.21-0.52, p < 0.001 and FFR r = 0.41, 95% CI: 0.26-0.55, p < 0.001)., Conclusion: Post-PCI RFR and FFR are associated with the subtended myocardial mass and the coronary volume to mass ratio. Vessels with higher mass and lower V/M ratio have lower post-PCI RFR and FFR., (© 2023 Wiley Periodicals LLC.)

Noninvasive methods of estimating invasively measured fractional flow reserve (FFR invasive ) are actively being explored, aiming to avoid the use of an invasive pressure wire and the administration of hyperemia-inducing drugs. Coronary angiography-derived FFR (FFR angio ) has already demonstrated its diagnostic performance in the context of stable coronary artery disease. However, its applicability in the context of non-ST-segment elevation myocardial infarction (NSTEMI) has yet to be established. We sought to determine the diagnostic performance of FFR angio exclusively in patients presenting with NSTEMI. We performed a prospective, single-center, single-arm, double-blinded study comparing FFR calculated by FFR angio to FFR invasive in NSTEMI patients. FFR invasive was measured in all angiographically intermediate lesions (30%-70% stenosis) and was then compared to FFR angio which was calculated at the same position, by a blinded operator. The primary endpoints were the sensitivity and specificity of FFR angio for predicting FFR invasive using a cut-off value of ≤0.80. Among 100 NSTEMI patients who were screened, 46 patients with 60 vessels in total underwent FFR invasive and were included in the study. The mean value of FFR invasive was 0.83 ± 0.3 with 22 (36%) being ≤0.80 while the mean FFR angio was 0.82 ± 0.1 with 22 (36%) being ≤0.80. FFR angio exhibited a sensitivity of 95.5%, a specificity of 97.4%, and a diagnostic accuracy of 96.7%. FFR angio can precisely and noninvasively estimate FFR invasive in acute coronary syndromes and may have a role in guiding treatment decisions related to angiographically intermediate coronary lesions in this context., What Is Known: FFR angio has demonstrated its diagnostic performance in validation studies, as a noninvasive and cost-effective method in the context of stable coronary artery disease but its performance has never been exclusively evaluated in NSTEMI patients., What Is New: The present prospective single-center study demonstrates the excellent diagnostic performance of FFR angio in detecting functionally significant coronary artery stenosis in the setting of NSTEMI, providing more confidence in utilizing FFR angio in this population, avoiding the risk of an invasive pressure wire and the administration of hyperemia-inducing drugs., What Is Next: Future randomized trials evaluating FFR angio -guided treatment of coronary artery disease (stable or ACS) are now needed to definitively establish the role of FFR angio in the physiological assessment of coronary lesions., (© 2022 Wiley Periodicals LLC.)

Aim: Microvascular resistance reserve (MRR) as derived from continuous intracoronary thermodilution specifically quantifies microvasculature function. As originally described, the technique necessitates reinstrumentation of the artery and manual reprogramming of the infusion pump when performing resting and hyperemic measurements. To simplify and to render this procedure operator-independent, we developed a fully automated method. The aim of the present study is to validate the automated procedure against the originally described one., Methods and Results: For the automated procedure, an infusion pump was preprogrammed to allow paired resting-hyperemic thermodilution assessment without interruption. To validate the accuracy of this new approach, 20 automated measurements were compared to those obtained in the same vessels with conventional paired resting-hyperemic thermodilution measurements (i.e., with a sensor pullback at each infusion rate and manual reprogramming of the infusion pump).  A close correlation between the conventional and the automated measuring technique was found for resting flow (Q rest : r = 0.89, mean bias = 2.52; SD = 15.47), hyperemic flow (Q hyper : r = 0.88, mean bias = -2.65; SD = 27.96), resting microvascular resistance (R μ-rest : r = 0.90, mean bias = 52.14; SD = 228.29), hyperemic microvascular resistance R μ-hyper : r = 0.92, mean bias = 12.95; SD = 57.80), and MRR (MRR: r = 0.89, mean bias = 0.04, SD = 0.59).  Procedural time was significantly shorter with the automated method (5'25″ ± 1'23″ vs. 4'36″ ± 0'33″, p = 0.013)., Conclusion: Continuous intracoronary thermodilution-derived measurements of absolute flow, absolute resistance, and MRR can be fully automated. This further shortens and simplifies the procedure when performing paired resting-hyperemic measurements., (© 2022 Wiley Periodicals LLC.)

Fractional flow reserve (FFR) pullbacks assess the location and magnitude of pressure drops along the coronary artery. The pullback pressure gradient (PPG) quantifies the FFR pullback curve and provides a numeric expression of focal versus diffuse coronary artery disease. This study aims (1) to validate the PPG using manual FFR pullbacks compared with motorized FFR pullbacks as a reference; and (2) to determine the intra- and interoperator reproducibility of the PPG derived from manual FFR pullbacks. Patients with stable coronary artery disease and an FFR ≤ 0.80 were included. All patients underwent FFR pullback evaluation either with a motorized device or manually, depending on the study cohort. The agreement of the PPG between repeated pullbacks was assessed using the Bland-Altman method. Overall, 116 FFR pullback maneuvers (96 manual and 20 motorized) were analyzed. There was excellent agreement between the PPG derived from manual and motorized pullbacks (mean difference -0.01 ± 0.07, 95% limits of agreement [LOA] -0.14 to 0.12). The intra- and interoperator reproducibility of PPG derived from manual pullbacks were excellent (mean difference <0.01, 95% LOA -0.11 to 0.12, and mean difference <0.01, 95% LOA -0.12 to 0.11, respectively). The duration of the pullback maneuver did not impact the reproducibility of the PPG (r = 0.12, 95% CI: -0.29 to 0.49, p = 0.567). Manual pullbacks allow for an accurate PPG calculation. The inter- and intraoperator reproducibility of PPG derived from manual pullbacks were excellent., (© 2022 Wiley Periodicals LLC.)

Objective: To investigate the impact of invasive functional guidance for coronary artery bypass graft surgery (CABG) on graft failure., Background: Data on the impact of fractional flow reserve (FFR) in guiding CABG are still limited., Methods: Systematic review and individual patient data meta-analysis were performed. Primary objective was the risk of graft failure, stratified by FFR. Risk estimates are reported as odds ratios (ORs) derived from the aggregated data using random-effects models. Individual patient data were analyzed using mixed effect model to assess relationship between FFR and graft failure. This meta-analysis is registered in PROSPERO (CRD42020180444)., Results: Four prospective studies comprising 503 patients referred for CABG, with 1471 coronaries, assessed by FFR were included. Graft status was available for 1039 conduits at median of 12.0 [IQR 6.6; 12.0] months. Risk of graft failure was higher in vessels with preserved FFR (OR 5.74, 95% CI 1.71-19.29). Every 0.10 FFR units decrease in the coronaries was associated with 56% risk reduction of graft failure (OR 0.44, 95% CI 0.34 to 0.59). FFR cut-off to predict graft failure was 0.79., Conclusion: Surgical grafting of coronaries with functionally nonsignificant stenoses was associated with higher risk of graft failure., (© 2021 The Authors. Catheterization and Cardiovascular Interventions published by Wiley Periodicals LLC.)

Objective: To assess the accuracy of coronary thermodilution measurements made with the RayFlow® infusion catheter., Background: Measurements of absolute coronary blood flow (ABF) and absolute microvascular resistance (R μ ) by continuous coronary thermodilution can be obtained in humans but their accuracy using a novel dedicated infusion catheter has not yet been validated. We compared ABF values obtained at different infusion rates to coronary blood flow (CBF) values obtained using flow probes, in swine., Methods: Twelve domestic swine were instrumented with coronary flow probes placed around the left anterior descending and circumflex coronary arteries. ABF was assessed with the RayFlow® infusion catheter during continuous saline infusion at fixed rates of 5 (n = 14), 10 (n = 15), 15 (n = 19), and 20 (n = 12) ml/min., Results: In the 60 measurements, ABF measured using thermodilution averaged 41 ± 17 ml/min (range from 17 to 90) and CBF values obtained with the coronary flow probes averaged 37 ± 18 ml/min (range from 8 to 87). The corresponding R μ values were 1532 ± 791 (range from 323 to 5103) and 1903 ± 1162 (range from 287 to 6000) Woods units using thermodilution and coronary flow probe assessments, respectively. ABF and R μ values measured using thermodilution were significantly correlated with the corresponding measurements obtained using coronary flow probes (R = 0.84 [0.73-0.95] and R = 0.80 [0.69-0.88], respectively)., Conclusions: ABF and R μ assessed by continuous saline infusion through a RayFlow® catheter closely correlate with measurements obtained with the gold standard coronary flow probes in a swine model., (© 2021 Wiley Periodicals LLC.)

Objectives: To characterize hemodynamics of serial coronary stenoses using fractional flow reserve (FFR) pullbacks and the pullback pressure gradients (PPG) index., Background: The cross-talk between stenoses within the same coronary artery makes the prediction of the functional contribution of each lesion challenging., Methods and Results: One-hundred seventeen patients undergoing coronary angiography for stable angina were prospectively recruited. Serial lesions were defined as two or more narrowings with visual diameter stenosis >50% on conventional angiography. Motorized FFR pullback tracings were obtained at 1 mm/s. Pullbacks were visually adjudicated as presenting two, one, and no focal pressure drops. The pattern of disease (i.e., focal or diffuse) was quantified using the PPG index. Twenty-five vessels presented serial lesions (mean PPG 0.48 ± 0.17). Two, one or no focal pressure drops were observed in 40% (n = 10; PPG 0.59 ± 0.17), 52% (n = 13; PPG 0.44 ± 0.12) and 8% of cases (n = 2; PPG 0.27 ± 0.01; p-value = 0.01). Distal FFR was similar between vessels with two, one and no focal pressure drops in the pullback curve (p-value = 0.27). The PPG index independently predicted the presence of two focal pressure drops in the pullback curve (p = 0.04)., Conclusions: FFR pullbacks in serial coronary lesions exhibit three distinct functional patterns. High PPG was associated with pullback curves presenting two pressure drops. The PPG provides a quantitative assessment of the pattern of coronary artery disease in cases with serial lesions and might be useful to assess the appropriateness of percutaneous revascularization., (© 2021 Wiley Periodicals LLC.)

Objectives: We sought to characterize the hemodynamic impact of mild coronary artery disease (CAD) using quantitative flow ratio (QFR, an angiography-derived fractional flow reserve [FFR]) in a population of patients with only non-significant CAD at baseline that subsequently experienced a myocardial infarction (MI)., Background: The discriminatory value of FFR in patients with mild CAD remains imperfect., Methods: We retrospectively included patients who underwent invasive coronary angiography for an MI, in whom another angiogram had been performed within the previous 5 years. Three-dimensional quantitative coronary angiography, QFR, and lesion length analysis were conducted on lesions responsible for the MI (future culprit lesions, [FCL]) as well as on control lesions (non-culprit lesions, [NCL])., Results: Eighty-three FCL and 117 NCL were analyzed in 83 patients: FCL were more severe (median % diameter of stenosis [DS] 39.1% [29.8; 45.7] vs. 29.8% [25.0; 37.2], p < .001), had lower QFR values (0.94 [0.86; 0.98] vs. 0.98 [0.96; 1.00], p < .001) and tended to be longer (15.2 mm [10.0; 27.3] vs. 12.7 mm [9.3; 22.4], p = .070) than NCL. In lesions with an interval < 2 years between baseline angiography and MI, the difference in QFR was more pronounced compared to the lesions with a longer interval (FCL: 0.92 [0.85; 0.97] vs. NCL: 0.98 [0.94; 1.00], p < .001 and FCL: 0.96 [0.88; 1.00] vs. NCL: 0.98 [0.96;1.00], p = .006 respectively) CONCLUSION: Mild coronary stenoses that are subsequently responsible for an MI (FCL) exhibit a higher DS and lower QFR years before the event. Furthermore, FCL with a lower QFR at baseline appear to lead earlier to MI., (© 2021 Wiley Periodicals LLC.)

Aims: In the randomized GRAFFITI trial, surgeons drew their strategy based on coronary angiography. When patients were randomized to fractional flow reserve (FFR)-guidance, surgeons were informed of the FFR values and asked to redraw their strategy. The aim of this study was to investigate the changes induced by FFR knowledge., Methods and Results: The intended and performed strategy (before and after FFR) were compared. Among 172 patients, 84 with 300 lesions were randomized to the FFR-guided group. The intended strategy was to bypass 236 stenoses:108 with a venous and 128 with an arterial graft. After disclosing FFR, a change in strategy occurred in 64 lesions (21.3%) of 48 (55%) patients. Among 64 lesions for which the intended strategy was medical therapy, 16 (25%) were bypassed after disclosing FFR. The number of procedures with >1 venous graft planned was significantly reduced from 37 to 27 patients (p = .031). The proportion of on-pump surgery was significantly reduced from 71 to 61 patients (p = .006). The rates of clinical events at 1 year were similar between patients with or without at least one change in strategy., Discussion: FFR-guided CABG is associated with a simplified surgical procedure in 55% of the patients, with similar clinical outcomes., (© 2021 Wiley Periodicals LLC.)

Objectives: The present study aimed at determining the accuracy and reproducibility of motorized FFR pullbacks in patients with stable coronary artery disease., Background: Fractional flow reserve (FFR) is recommended for decision making regarding myocardial revascularization. The distribution of epicardial resistance along coronary vessels can be assessed using FFR pullbacks., Methods: Duplicated FFR pullbacks were acquired using a motorized device at a speed of 1 mm/s in intermediate coronary stenosis. In addition, a single FFR value was measured at an anatomical landmark. The agreement between FFR measurements was assessed using the Bland-Altman method, Pearson's correlation coefficient and area under the pullback curve (AUPC)., Results: In 20 vessels, 37,326 FFR values were obtained. The mean FFR from the pullbacks was 0.91 ± 0.08 whereas the mean FFR at the distal location was 0.85 ± 0.09. The mean difference between pullbacks was -0.002 (LOA -0.058 to 0.054). The difference in AUPC between the two FFR pullbacks was 2.1 ± 1.6%. At pre-specified anatomical locations, the mean difference between the FFR derived from the pullback data and the measured FFR was 0 (LOA -0.040 to 0.039). The repeatability of the distal FFR measurement was high (bias -0.003, LOA -0.046 to 0.041)., Conclusion: A motorized FFR pullback was accurate to assess the distribution of epicardial resistance in patients with intermediate coronary artery disease. The reproducibility of the FFR pullback was high. Further studies are required to determine the potential usefulness of a hyperemic FFR pullback strategy for decision making and treatment planning., (© 2020 Wiley Periodicals, Inc.)

Objectives: We sought to develop an automatic method for correcting common errors in phasic pressure tracings for physiology-guided interventions on coronary and valvular stenosis., Background: Effective coronary and valvular interventions rely on accurate hemodynamic assessment. Phasic (subcycle) indexes remain intrinsic to valvular stenosis and are emerging for coronary stenosis. Errors, corrections, and clinical implications of fluid-filled catheter phasic pressure assessments have not been assessed in the current era of ubiquitous, high-fidelity pressure wire sensors., Methods: We recruited patients undergoing invasive coronary physiology assessment. Phasic aortic pressure signals were recorded simultaneously using a fluid-filled guide catheter and 0.014″ pressure wire before and after standard calibration as well as after pullback. We included additional subjects undergoing hemodynamic assessment before and after transcatheter aortic valve implantation. Using the pressure wire as reference standard, we developed an automatic algorithm to match phasic pressures., Results: Removing pressure offset and temporal shift produced the largest improvements in root mean square (RMS) error between catheter and pressure wire signals. However, further optimization <1 mmHg RMS error was possible by accounting for differential gain and the oscillatory behavior of the fluid-filled guide. The impact of correction was larger for subcycle (like systole or diastole) versus whole-cycle metrics, indicating a key role for valvular stenosis and emerging coronary pressure ratios., Conclusions: When calibrating phasic aortic pressure signals using a pressure wire, correction requires these parameters: offset, timing, gain, and oscillations (frequency and damping factor). Automatically eliminating common errors may improve some clinical decisions regarding physiology-based intervention., (© 2020 The Authors. Catheterization and Cardiovascular Interventions published by Wiley Periodicals, Inc.)

Objectives: To identify clinical, angiographic and hemodynamic predictors of discordance between instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR)., Background: The iFR was found to be non-inferior to the gold-standard FFR for guiding coronary revascularization, although it is discordant with FFR in 20% of cases. A better understanding of the causes of discordance may enhance application of these indices., Methods: Both FFR and iFR were measured in the prospective multicenter CONTRAST study. Clinical, angiographic and hemodynamic variables were compared between patients with concordant values of FFR and iFR (cutoff ≤0.80 and ≤0.89, respectively)., Results: Out of the 587 patients included, in 466 patients (79.4%) FFR and iFR agreed: both negative, n = 244 (41.6%), or positive, n = 222 (37.8%). Compared with FFR, iFR was negative discordant (FFR+/iFR-) in 69 (11.8%) patients and positive discordant (FFR-/iFR+) in 52 (8.9%) patients. On multivariate regression, stenosis location (left main or proximal left anterior descending) (OR: 3.30[1.68;6.47]), more severe stenosis (OR: 1.77[1.35;2.30]), younger age (OR: 0.93[0.90;0.97]), and slower heart rate (OR: 0.59[0.42;0.75]) were predictors of a negative discordant iFR. Absence of a beta-blocker (OR: 0.41[0.22;0.78]), older age (OR: 1.04[1.00;1.07]), and less severe stenosis (OR: 0.69[0.53;0.89]) were predictors of a positive discordant iFR., Conclusions: During iFR acquisition, stenosis location, stenosis degree, heart rate, age and use of beta blockers influence concordance with FFR and should be taken into account when interpreting iFR., (© 2019 Wiley Periodicals, Inc.)

Objectives: to compare the occurrence of clinical events in diabetics treated with the Absorb bioresorbable vascular scaffold (Absorb BVS; Abbott Vascular, Santa Clara, CA) versus everolimus-eluting metal stents (EES; XIENCE V; Abbott Vascular, Santa Clara, CA) BACKGROUND: There are limited data dedicated to clinical outcomes of diabetic patients treated with bioresorbable scaffolds (BRS) at 2-year horizon., Methods: The present study included 812 patients in the ABSORB EXTEND study in which a total of 215 diabetic patients were treated with Absorb BVS. In addition, 882 diabetic patients treated with EES in pooled data from the SPIRIT clinical program (SPIRIT II, SPIRIT III and SPIRIT IV trials) were used for comparison by applying propensity score matching using 29 different variables. The primary endpoint was ischemia driven major adverse cardiac events (ID-MACE), including cardiac death, myocardial infarction (MI), and ischemia driven target lesion revascularization (ID-TLR)., Results: After 2 years, the ID-MACE rate was 6.5% in the Absorb BVS vs. 8.9% in the Xience group (P = 0.40). There was no difference for MACE components or definite/probable device thrombosis (HR: 1.43 [0.24,8.58]; P = 0.69). The occurrence of MACE was not different for both diabetic status (insulin- and non-insulin-requiring diabetes) in all time points up to the 2-year follow-up for the Absorb and Xience groups., Conclusion: In this largest ever patient-level pooled comparison on the treatment of diabetic patients with BRS out to two years, individuals with diabetes treated with the Absorb BVS had a similar rate of MACE as compared with diabetics treated with the Xience EES. © 2017 Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)

Objective: We propose a novel technique called pressure-bounded coronary flow reserve (pb-CFR) and demonstrate its application to the randomized DEFER trial., Background: Intracoronary flow reserve assessment remains underutilized relative to pressure measurements partly due to less robust tools., Methods: While rest and hyperemic intracoronary pressure measurements cannot quantify CFR exactly, they do provide upper and lower bounds. We validated pb-CFR invasively against traditional CFR, then applied it to high fractional flow reserve (FFR ≥ 0.75) lesions in DEFER randomized to revascularization or medical therapy., Results: pb-CFR showed an 84.4% accuracy to predict invasive CFR < 2 or CFR ≥ 2 in 107 lesions. In its proof of concept application to DEFER lesions with FFR ≥ 0.75, the 28 with pb-CFR < 2 compared to 28 with pb-CFR ≥ 2 had a non-significant reduction in freedom from angina (61% vs. 71% at 5 years, P = 0.57) and a non-significantly higher rate of major adverse cardiac events (MACE, 25% vs. 15%, P = 0.34). Lesions with FFR ≥ 0.75 but pb-CFR < 2 showed no difference in freedom from angina (61% vs. 50%, P = 0.54) or MACE (25% vs. 38%, P = 0.27) between the 28 randomized to medical therapy and the 16 randomized to revascularization., Conclusions: pb-CFR offers a new method for studying FFR/CFR discordances using regular pressure wire measurements. As an example application, DEFER suggested that low pb-CFR with high FFR may be a risk marker for more angina and worse outcomes, but that this risk cannot be modified by revascularization. © 2017 Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)

Objective: To assess midterm (3 years) clinical outcomes of transcatheter aortic valve implantation (TAVI) in Belgium using the Edwards SAPIEN valve or the Medtronic CoreValve transcatheter heart valve (THV)., Background: Medium and long term follow-up data of both THVs are still relatively scarce, although of great clinical relevance for a relatively new but rapidly expanding treatment modality. Therefore, reporting mid- and long term clinical outcome data, coming from large "real world" national registries, remains contributive., Methods: Between December 2007 and March 2012, 861 "real world" patients who were not candidates for surgical aortic valve replacement as decided by the local heart teams, underwent TAVI at 23 sites. Eleven sites exclusively used SAPIEN THV (n = 460), while 12 exclusively used CoreValve THV (n = 401). Differences in clinical outcomes by valve system were assessed, according to access route and baseline EuroSCORE risk profile (<10%: low, 10-20%: intermediate and >20%: high risk)., Results: Overall cumulative survival at 3 years was 51% for SAPIEN vs. 60% for CoreValve (P = 0.021). In transfemorally treated patients, SAPIEN and CoreValve had similar survival at 3 years for each of the baseline EuroSCORE cohorts (low risk: 72% vs. 76%, P = 0.45; intermediate risk: 62% vs. 59%, P = 0.94; high risk: 48% vs. 53%, P = 0.65)., Conclusion: Cumulative midterm 3 year survival after transfemoral TAVI in "real world" patients refused for surgery with similar baseline EuroSCORE risk profile is not different between SAPIEN or CoreValve., (© 2015 Wiley Periodicals, Inc.)

Objectives: To compare the effective radiation dose (ERD) needed to obtain information on coronary anatomy and physiology by a non-invasive versus an invasive diagnostic strategy., Background: Knowledge of anatomy and physiology is needed for management of patients with coronary artery disease (CAD). There is, however, a growing concern about detrimental long-term effects of radiation associated with diagnostic procedures., Methods: In a total of 671 patients with suspected CAD, we compared the ERD needed to obtain anatomical and physiological information through a non-invasive strategy or an invasive strategy. The non-invasive strategy consisted of coronary computed tomography angiography (CCTA) and single photon emission computed tomography (SPECT). The invasive strategy included coronary angiography (CA) and fractional flow reserve (FFR) measurement. In 464 patients, the data were acquired in Period 2009 and in 207 the data were acquired in Period 2011 (after each period, the CCTA- and the CA-equipment had been upgraded)., Results: For the Period 2009 total ERD of the non-invasive approach was significantly larger compared to the invasive approach (28.45 ± 5.37 mSv versus 15.79 ± 7.95 mSv, respectively; P < 0.0001). For Period 2011, despite the significant decrease in ERD for both groups (P<0.0001 for both), the ERD remained higher for the non-invasive approach compared to the invasive approach (16.67 ± 10.45 mSv vs. 10.36 ± 5.87 mSv, respectively; P < 0.0001). Simulation of various diagnostic scenarios showed cumulative radiation dose is the lowest when a first positive test is followed by an invasive strategy., Conclusion: To obtain anatomic and physiologic information in patients with suspected CAD, the combination of CA and FFR is associated with lower ERD than the combination of CCTA and SPECT., (© 2014 Wiley Periodicals, Inc.)

Aim: To assess ACEF (age, creatinine, and ejection fraction) and Clinical SYNTAX (CSS) score in the risk stratification of patients with heavily calcified stenosis undergoing rotational atherectomy with stent implantation (rota-stenting)., Methods and Results: ACEF and CSS were calculated in 221 consecutive patients with stable angina undergoing rota-stenting. Mean age of the patients was 74 ± 10 years, left ventricular ejection fraction was 61 ± 18%, and final burr size 1.78 ± 0.24 mm, with 2.6 ± 0.9 burrs used for each patient. Primary end-point was MACE at one-year defined as the composite of cardiac death, myocardial infarction, and target vessel revascularization. Post-hoc analysis was performed by stratifying the clinical outcome according to ACEF and CSS tertiles. At 1 year there was a significantly higher MACE rate in the high tertile of ACEF (24% for ACEFHigh vs. 13% for ACEFMid vs. 9% for ACEFLow; P = 0.017) and CSS (25% for CSSHigh vs. 12% for CSSMid vs. 8% for CSSLow; P = 0.008). The predictive accuracy for both ACEF and CSS was moderate (c-statistics, 0.629 and 0.638, respectively)., Conclusion: Both ACEF and CSS predict with moderate accuracy MACE at 1-year in patients with heavily calcified coronary stenosis undergoing rotational atherectomy with stent implantation., (Copyright © 2014 Wiley Periodicals, Inc.)

Background: Previous studies failed to assess the individual prognostic role of thrombus aspiration (TA) or abciximab in primary percutaneous coronary intervention (pPCI), due their prevalent combined use., Methods and Results: A total of 644 consecutive ST-segment elevation myocardial infarction patients treated with pPCI were included in this retrospective registry from January 2006 to December 2008. Patients were divided in: (a) Group 1, with conventional pPCI; (b) Group 2, with pPCI and abciximab; (c) Group 3, with pPCI and TA; (d) Group 4, with pPCI and abciximab plus TA. Primary end point was the composite of major adverse cardiovascular events (MACEs, defined as overall mortality, myocardial infarction, target vessel revascularization, and major bleedings) at 1 year. Baseline clinical and angiographic characteristics were not different among the groups, with the exception of a younger age in group 4. The two groups of patients treated with TA (group 3 and 4) received more frequently direct stenting (P < 0.001 vs. group 1 for both), presented higher rate of end-procedural TIMI flow grade 3 (P < 0.001 vs. group 1 for both), and lower rate of no-reflow (P = 0.016 and P < 0.001 vs. group 1, respectively). Patients of group 2 presented a borderline nonsignificant trend toward higher rate of end-procedural TIMI flow grade 3 (P = 0.083 vs. group 1). MACEs at 1 year were 43 (29%) in group 1 versus 25 (22%) in group 2 versus 24 (19%) in group 3 versus 32 (13%) in group 4 (log-rank P = 0.001). At the multivariate Cox regression analysis, combined TA plus abciximab in group 4 [hazard ratio (HR): 0.48, confidence interval (CI) 95% 0.28-0.84, P = 0.01] and a higher left ventricular ejection fraction (HR: 0.97, CI 95% 0.95-0.98, P < 0.001) were significantly associated with lower MACE rate., Conclusions: The combination of pharmacologic and mechanic antithrombotic treatment during pPCI was associated with better 1-year clinical outcome., (Copyright © 2013 Wiley Periodicals, Inc.)

Objective: To compare the geometrical parameters of a bioresorbable vascular scaffold (BVS) with a standard metallic stent., Background: The introduction of polymeric bioresorbable materials in the design of novel coronary scaffolds may affect some geometrical parameters, such as eccentricity and symmetry indices, previously introduced as IVUS criteria for optimal metallic stent deployment., Methods: From ABSORB Cohort A, ABSORB Cohort B, SPIRIT I, and SPIRIT II, all patients implanted with BVS 1.0, BVS 1.1, or XIENCE V, respectively and intravascular ultrasound analyses post-implantation were selected. The eccentricity index was calculated frame by frame and expressed as an average per device (minimum diameter/maximum diameter). The symmetry index of the device was reported as ([maximum diameter - minimum diameter]/maximum diameter). Six months major adverse cardiac events (MACE) were analyzed., Results: A total of 242 patients were selected (BVS 1.0: n = 28, BVS 1.1: n = 94, XIENCE V: n = 120). The BVS exhibited a significantly lower eccentricity index (BVS 1.0: 0.83 ± 0.09; BVS 1.1: 0.85 ± 0.08; XIENCE V: 0.90 ± 0.06; P < 0.01) and a significantly higher symmetry index (BVS 1.0: 0.30 ± 0.07; BVS 1.1: 0.31 ± 0.06, XIENCE V 0.26 ± 0.07; P < 0.01) as compared to the XIENCE V. An inverse correlation was found between the symmetry and eccentricity indices for both (BVS r = -0.69, P < 0.01; XIENCE V r = -0.61, P < 0.01). No differences in MACE were detected between the groups according to their geometrical parameters., Conclusions: The introduction of a new polymeric material in the design of BVS resulted in a lower eccentricity index and a higher symmetry index as compared to metallic stents, without detectable impact in MACE, at 6 months., (Copyright © 2011 Wiley Periodicals, Inc.)

Objectives: The ABSORB cohort A trial using the bioresorbable everolimus-eluting scaffold (BVS revision 1.0, Abbott Vascular) demonstrated a slightly higher acute recoil with BVS than with metallic stents. To reinforce the mechanical strength of the scaffold, the new BVS scaffold (revision 1.1) with modified strut design was developed and tested in the ABSORB cohort B trial. This study sought to evaluate and compare the in vivo acute scaffold recoil of the BVS revision 1.0 in ABSORB cohort A and the BVS revision 1.1 in ABSORB cohort B with the historical recoil of the XIENCE V® everolimus-eluting metal stent (EES, SPIRIT I and II)., Methods: In the ABSORB cohort B trial, 101 patients with one or two de-novo lesions were enrolled at 10 sites. In ABSORB cohort A, 27 patients treated with a BVS 1.0 were analyzed and compared with EES. Acute absolute recoil, assessed by quantitative coronary angiography, was defined as the difference between mean diameter of the last inflated balloon at the highest pressure (X) and mean lumen diameter of the stent immediately after the last balloon deflation (Y). Acute percent recoil was defined as (X - Y)/X and expressed as a percentage., Results: Out of 101 patients enrolled in the ABSORB cohort B trial, 88 patients are available for complete analysis of acute recoil. Absolute recoil of BVS 1.1 (0.19 ± 0.18 mm) was numerically higher than metallic EES (vs. 0.13 ± 0.21 mm) and similar to BVS 1.0 (0.20 ± 0.21 mm) but the differences did not reach statistical significance (P = 0.40). The acute percent recoil demonstrated the same trend (EES: 4.3% ± 7.1%, BVS 1.0: 6.9% ± 7.0%, BVS 1.1: 6.7% ± 6.4%, P = 0.22). In the multivariate regression model, high balloon/artery ratio (>1.1) (OR 1.91 [1.34-2.71]) was the predictive for high absolute recoil (>0.27 mm) while (larger) preprocedural MLD was protective (OR 0.84 [0.72-0.99]). The stent/scaffold type was not a predictor of acute recoil., Conclusions: The average in vivo acute scaffold recoil of the BVS 1.1 is slightly higher than the metallic EES. However, the scaffold/stent type was not predictive of high acute recoil, while implantation in undersized vessels or usage of oversized devices might confound the results., (Copyright © 2011 Wiley-Liss, Inc.)

Coronary pressure measurement has emerged as one of the most promising tool to assist interventional cardiologist to make accurate clinical decisions. Fractional flow reserve (FFR) is a simple way of reliably assessing the functional consequences of coronary atherosclerosis. The training in FFR is easy, and coronary pressure measurements can be obtained swiftly in the catheterization laboratory. This review outlines the practical set up of FFR in the catheterization laboratory and also discusses the potential pitfalls in the measurement of FFR., (Copyright © 2010 Wiley-Liss, Inc.)

Objectives: To evaluate the effect of thrombus aspiration in a real-world all-comer patient population with STEMI undergoing primary PCI., Background: Catheter thrombus aspiration in primary PCI was beneficial in randomized clinical trials., Methods: We enrolled 313 STEMI patients presenting with TIMI Flow Grade 0 or 1 in the infarct related artery at baseline angiogram undergoing primary PCI. PATIENTS were divided in two groups based on whether thrombus aspiration was attempted. This decision was left at operator's discretion. Procedural and long-term clinical outcomes were compared between the two groups., Results: Baseline characteristics were similar between groups: 194 (62%) received thrombus aspiration and 119 underwent conventional PCI. Thrombus aspiration was associated with significantly lower post-PCI TIMI Frame Count values (19 +/- 15 vs. 25 +/- 17; P = 0.002) and higher TIMI Flow Grade 3 (92% vs. 73%; P < 0.001). Postprocedural myocardial perfusion assessed by myocardial blush grade (MBG) was significantly increased in the thrombus aspiration group (MBG 3: 44% vs. 21%; P < 0.001). No significant difference was found between the two groups in clinical outcome at 30 days. At one year, patients treated with thrombus aspiration showed significantly higher overall survival (HR 0.41, 95% CI 0.20-0.81; log-rank P = 0.010) and MACE-free survival (HR 0.49, 95% CI 0.28-0.85; log-rank P = 0.011)., Conclusions: In real-world all-comer STEMI patients with occluded infarct-related artery, thrombus aspiration prior to PCI improves coronary flow, myocardial perfusion, and long-term clinical outcome as compared with PCI in the absence of thrombus aspiration., ((c) 2010 Wiley-Liss, Inc.)

Background: Intracoronary thermography has been proposed to detect vulnerable plaques. We hypothesized that changes in coronary pressure and flow in the coronary tree may interfere with the temperature measurements obtained with thermistors., Methods and Results: First, a very close correlation was found in vitro between the temperature measured by a thermocouple and by a thermistor-based temperature measuring guide wire (PressureWire, PW) over a large temperature range. Second, the PW was tested in a vitro low pressure model of "hot plaque". The sensor of the PW could detect changes in temperature of the wall of 0.5 degrees C as long as the distance from the wall was less than 0.5 mm and the flow less than 60 mL/min. Third, in 18 patients with an acute myocardial infarction, intracoronary pressure and temperature variations were assessed. Although crossing the occlusion, the temperature rose by 0.059 +/- 0.02 degrees C and this increase was correlated with the distal coronary pressure (r = 0.72, P < 0.001). Fourth, a balloon coronary occlusion (BCO) with the sensor distally in the distal part of the vessel (low flow/low pressure conditions) systematically induced an increase in temperature (0.14 +/- 0.07 degrees C) while with the sensor proximally to the balloon occlusion (low flow/normal pressure conditions), no change occurred., Conclusion: Taken together these observations suggest that thermistor-based sensors are not suited for assessing thermal heterogeneity in the vascular wall and that the data obtained so far in patients with acute coronary syndromes might have been flawed by pressure (and flow) artifacts., ((c) 2009 Wiley-Liss, Inc.)

Background: Despite their controversial effect, "renal" doses of dopamine (3-5 microg kg(-1) min(-1)) are often used in intensive care units to preserve renal function and to improve final outcome., Aim: To assess the effects of different doses of dopamine on renal blood flow in patients with normal renal function and in patients with renal dysfunction., Methods and Results: In 17 patients with normal renal function and in 12 patients with moderate renal dysfunction, mean arterial pressure (MAP), heart rate (HR), and average peak renal flow velocities (FlowWire APV) were continuously recorded at baseline and during IV administration of increasing dopamine doses (3, 5, 10, 20, and 30 microg kg(-1) min(-1)). MAP and HR did not change during infusion of 3-5 microg kg(-1) min(-1) but increased to the same extent in both groups during infusion of >10 microg kg(-1) min(-1). Baseline APV was similar in both groups. Infusion of 3-5 mug . kg(-1) . min(-1) induced a significant change in APV only in patients with normal renal function. In patients with renal dysfunction, APV increased only during infusion of >10 microg kg(-1) min(-1) in parallel with MAP and HR., Conclusion: "Renal" doses of dopamine increase renal blood flow in normals but not in patients with moderate renal dysfunction., ((c) 2008 Wiley-Liss, Inc.)

Objectives: This study sought to evaluate and compare in vivo acute stent recoil of a novel bioabsorbable stent and a metallic stent., Background: The bioabsorbable everolimus-eluting coronary stent (BVS) is composed of a poly-L-lactic acid backbone, coated with a bioabsorbable polymer containing the antiproliferative drug, everolimus, and expected to be totally metabolized and absorbed in the human body. Because the BVS is made from polymer, it may have more acute recoil than metallic stents in vivo., Methods: A total of 54 patients, who underwent elective stent implantation for single de novo native coronary artery lesions, were enrolled: 27 patients treated with the BVS and 27 patients treated with the everolimus-eluting cobalt chromium stent (EES). Acute absolute recoil, assessed by quantitative coronary angiography, was defined as the difference between mean diameter of the last inflated balloon at the highest pressure (X) and mean lumen diameter of the stent immediately after the last balloon deflation (Y). Acute percent recoil was defined as (X - Y)/X and expressed as a percentage., Results: Acute absolute recoil of the BVS and EES was 0.20 +/- 0.21 mm and 0.13 +/- 0.21 mm, respectively (P = 0.32). Acute percent recoil was 6.9% +/- 7.0% in the BVS group and 4.3% +/- 7.1% in the EES group (P = 0.25)., Conclusions: In vivo acute stent recoil of the BVS is slightly larger but insignificantly different from that of the EES, implying that the BVS may have good radial strength similar to the metallic stent., ((c) 2007 Wiley-Liss, Inc.)

By injecting a few cubic centimeters of saline into the coronary artery and using thermodilution principles, mean transit time (T(mn)) of the injectate can be calculated and is inversely proportional to coronary blood flow. Because microvascular resistance equals distal coronary pressure (P(d)) divided by myocardial flow, the product P(d). T(mn) provides an index of myocardial resistance (IMR). In this in vitro study in a physiologic model of the coronary circulation, we compared IMR to true myocardial resistance (TMR) at different degrees of myocardial resistance and at different degrees of epicardial stenosis. Absolute blood flow was varied from 42 to 203 ml/min and TMR varied from 0.39 to 1.63 dynes. sec/cm(5). Inverse mean transit time correlated well to absolute blood flow (R(2) = 0.93). Furthermore, an excellent correlation was found between IMR and TMR (R(2) = 0.94). IMR was independent on the severity of epicardial stenosis and thus specific for myocardial resistance. Thus, using one single guidewire, both fractional flow reserve and IMR can be measured simultaneously as indexes of epicardial and microvascular disease, respectively, enabling separate assessment of both coronary arterial and microvascular disease., (Copyright 2004 Wiley-Liss, Inc.)

Guidewire-based coronary pressure measurement has emerged over the last years as a promising approach in the invasive assessment of coronary artery disease. It enables calculation of fractional flow reserve (FFR) which closely relates distal coronary pressure to myocardial blood flow during maximal arteriolar vasodilation. Coronary pressure measurement and FFR provide important information, both for decision making in diagnostic angiography and for monitoring and evaluating coronary interventions. In this review, the practical set-up of coronary pressure measurement in the catheterization laboratory is discussed step-by-step, special attention is given to potential pitfalls and how to avoid them, and the interpretation of coronary pressure measurement in a variety of pathologic conditions is clarified. Cathet. Cardiovasc. Intervent. 49:1-16, 2000., (Copyright 2000 Wiley-Liss, Inc.)

Presence, extent, and evolution of atherosclerotic coronary narrowings, as well as the anatomic possibilities for revascularization, can be reliably defined at (and only at) selective coronary angiography. The latter remains, therefore, the pivotal diagnostic tool for patients with suspected coronary artery disease. However, in spite of the increasing availability of on-line quantitative coronary angiography, it still holds that the functional (physiologic) consequences of an epicardial coronary narrowing cannot be completely derived from geometric (anatomic) information. Clinical decision making can be particularly difficult in lesions of intermediate severity (40-70% diameter reduction), in postinterventional segments, and in some particular anatomic settings, namely, ostial stenoses, bifurcation lesions, and diffuse atherosclerotic disease. This has led to an explosive growth of new methods for assessing the physiological significance of coronary narrowings documented at angiography. Among them, Doppler blood flow velocitometry and transstenotic pressure gradient measurements have emerged as the only techniques easily applicable in most catheterization laboratories. Here, we briefly review the clinical interest of measuring transstenotic pressure gradients.

When performing coronary angioplasty, guide catheter intubation of the ostium often leads to a damping of the pressure tracing. In contrast, when a guide catheter with side holes is used, the pressure tracing is most often superimposable to the pressure wave recorded through the side arm of a femoral artery sheath introducer. This pressure wave gives the reassuring impression of normal hemodynamics in the coronary artery. To illustrate the role of guide catheter side holes and that guide catheter pressure does not necessarily equal the actual coronary artery perfusion pressure, we report observations on trans-ostial pressure gradients at rest and during increased coronary flow rates. An abbreviated in vivo study of side holes on the maximal achievable blood flow, employing timed blood flow collections in 7F and 8F side hole guide catheters, was made in 10 patients. At high mean aortic pressure levels, the blood flow through the side holes did not exceed 80 and 60 mL/min for 8 and 7F guide catheters, respectively. These observations suggest that, under some conditions, the guide catheter may produce a resting or hyperemic trans-ostial gradient and that the flow provided only by the side holes of guide catheter is limited. Guide catheter interference with normal flow should be considered in interventional procedures even when arterial pressure appears normal.