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Background and Aims: This study aimed to evaluate clinical outcomes in patients developing post-operative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG) and characterize variations in oral anticoagulation (OAC) use, benefits, and complications., Methods: A systematic search identified studies on new-onset POAF after CABG and OAC initiation. Outcomes included risks of thromboembolic events, bleeding, and mortality. Furthermore, a meta-analysis was conducted on these outcomes, stratified by the use or non-use of OAC., Results: The identified studies were all non-randomized. Among 1 698 307 CABG patients, POAF incidence ranged from 7.9% to 37.6%. Of all POAF patients, 15.5% received OAC. Within 30 days, thromboembolic events occurred at rates of 1.0% (POAF: 0.3%; non-POAF: 0.8%) with 2.0% mortality (POAF: 1.0%; non-POAF: 0.5%). Bleeding rates were 1.1% for POAF patients and 2.7% for non-POAF patients. Over a median of 4.6 years, POAF patients had 1.73 thromboembolic events, 3.39 mortality, and 2.00 bleeding events per 100 person-years; non-POAF patients had 1.14, 2.19, and 1.60, respectively. No significant differences in thromboembolic risks [effect size -0.11 (-0.36 to 0.13)] and mortality [effect size -0.07 (-0.21 to 0.07)] were observed between OAC users and non-users. However, OAC use was associated with higher bleeding risk [effect size 0.32 (0.06-0.58)]., Conclusions: In multiple timeframes following CABG, the incidence of complications in patients who develop POAF is low. The use of OAC in patients with POAF after CABG is associated with increased bleeding risk., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: While experimental data suggest that selective intracoronary hypothermia decreases infarct size, studies in patients with ST-elevation myocardial infarction (STEMI) are lacking., Aims: We investigated the efficacy of selective intracoronary hypothermia during primary percutaneous coronary intervention (PCI) to decrease infarct size in patients with STEMI., Methods: In this multicentre randomised controlled trial, 200 patients with large anterior wall STEMI were randomised 1:1 to selective intracoronary hypothermia during primary PCI or primary PCI alone. Using an over-the-wire balloon catheter for infusion of cold saline and a pressure-temperature wire to monitor the intracoronary temperature, the anterior myocardium distal to the occlusion was selectively cooled to 30-33°C for 7-10 minutes before reperfusion (occlusion phase), immediately followed by 10 minutes of cooling after reperfusion (reperfusion phase). The primary endpoint was infarct size as a percentage of left ventricular mass on cardiovascular magnetic resonance imaging after 3 months., Results: Selective intracoronary hypothermia was performed in 94/100 patients randomised to cooling. Distal coronary temperature decreased by 6°C within 43 seconds (interquartile range [IQR] 18-113). The median duration of the occlusion phase and reperfusion phase were 8.2 minutes (IQR 7.2-9.0) and 9.1 minutes (IQR 8.2-10.0), respectively. The infarct size at 3 months was 23.1±12.5% in the selective intracoronary hypothermia group and 21.6±12.2% in the primary PCI alone group (p=0.43). The left ventricular ejection fraction at 3 months in each group were 49.1±10.2% and 50.1±10.4%, respectively (p=0.53)., Conclusions: Selective intracoronary hypothermia during primary PCI in patients with anterior wall STEMI was feasible and safe but did not decrease infarct size compared with standard primary PCI. (ClinicalTrials.gov: NCT03447834).

Background: Myocardial ischaemia results from insufficient coronary blood flow. Computed virtual fractional flow reserve (vFFR) allows quantification of proportional flow loss without the need for invasive pressure-wire testing. In the current study, we describe a novel, conductivity model of side branch flow, referred to as 'leak'. This leak model is a function of taper and local pressure, the latter of which may change radically when focal disease is present. This builds upon previous techniques, which either ignore side branch flow, or rely purely on anatomical factors. This study aimed to describe a new, conductivity model of side branch flow and compare this with established anatomical models., Methods and Results: The novel technique was used to quantify vFFR, distal absolute flow (Qd) and microvascular resistance (CMVR) in 325 idealised 1D models of coronary arteries, modelled from invasive clinical data. Outputs were compared to an established anatomical model of flow. The conductivity model correlated and agreed with the reference model for vFFR (r = 0.895, p < 0.0001; ＋0.02, 95% CI 0.00 to ＋ 0.22), Qd (r = 0.959, p < 0.0001; -5.2 mL/min, 95% CI -52.2 to ＋13.0) and CMVR (r = 0.624, p < 0.0001; ＋50 Woods Units, 95% CI -325 to ＋2549)., Conclusion: Agreement between the two techniques was closest for vFFR, with greater proportional differences seen for Qd and CMVR. The conductivity function assumes vessel taper was optimised for the healthy state and that CMVR was not affected by local disease. The latter may be addressed with further refinement of the technique or inferred from complementary image data. The conductivity technique may represent a refinement of current techniques for modelling coronary side-branch flow. Further work is needed to validate the technique against invasive clinical data., Competing Interests: Declaration of competing interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. This independent research was carried out at the National Institute for Health and Care Research (NIHR) Sheffield Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care., (Crown Copyright © 2024. Published by Elsevier Ltd. All rights reserved.)

Aims: Ischaemic heart disease results from insufficient coronary blood flow. Direct measurement of absolute flow (mL/min) is feasible, but has not entered routine clinical practice in most catheterization laboratories. Interventional cardiologists, therefore, rely on surrogate markers of flow. Recently, we described a computational fluid dynamics (CFD) method for predicting flow that differentiates inlet, side branch, and outlet flows during angiography. In the current study, we evaluate a new method that regionalizes flow along the length of the artery., Methods and Results: Three-dimensional coronary anatomy was reconstructed from angiograms from 20 patients with chronic coronary syndrome. All flows were computed using CFD by applying the pressure gradient to the reconstructed geometry. Side branch flow was modelled as a porous wall boundary. Side branch flow magnitude was based on morphometric scaling laws with two models: a homogeneous model with flow loss along the entire arterial length; and a regionalized model with flow proportional to local taper. Flow results were validated against invasive measurements of flow by continuous infusion thermodilution (Coroventis™, Abbott). Both methods quantified flow relative to the invasive measures: homogeneous ( r 0.47, P 0.006; zero bias; 95% CI -168 to +168 mL/min); regionalized method ( r 0.43, P 0.013; zero bias; 95% CI -175 to +175 mL/min)., Conclusion: During angiography and pressure wire assessment, coronary flow can now be regionalized and differentiated at the inlet, outlet, and side branches. The effect of epicardial disease on agreement suggests the model may be best targeted at cases with a stenosis close to side branches., Competing Interests: Conflict of interest: P.D.M. is named as an inventor on a University of Sheffield patent that describes elements of the CFD method. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Determining the functional significance of each individual coronary lesion in patients with serial coronary stenoses is challenging. It has been proposed that nonhyperemic pressure ratios, such as the instantaneous wave free ratio (iFR) and the ratio of resting distal to proximal coronary pressure (Pd/Pa) are more accurate than fractional flow reserve (FFR) because autoregulation should maintain stable resting coronary flow and avoid hemodynamic interdependence (cross-talk) that occurs during hyperemia. This study aimed to measure the degree of hemodynamic interdependence of iFR, resting Pd/Pa, and FFR in a porcine model of serial coronary stenosis., Methods: In 6 anesthetized female swine, 381 serial coronary stenoses were created in the left anterior descending artery using 2 balloon catheters. The degree of hemodynamic interdependence was calculated by measuring the absolute changes in iFR, resting Pd/Pa, and FFR across the fixed stenosis as the severity of the other stenosis varied., Results: The hemodynamic interdependence of iFR, resting Pd/Pa, and FFR was 0.039±0.048, 0.021±0.026, and 0.034±0.034, respectively (all P <0.001). When the functional significance of serial stenoses was less severe (0.70-0.90 for each index), the hemodynamic interdependence was 0.009±0.020, 0.007±0.013, and 0.017±0.022 for iFR, resting Pd/Pa, and FFR, respectively (all P <0.001). However, in more severe serial coronary stenoses (<0.60 for each index), hemodynamic interdependence was 0.060±0.050, 0.037±0.030, and 0.051±0.037 for iFR, resting Pd/Pa, and FFR, respectively (all P <0.001)., Conclusions: When assessing serial coronary stenoses, nonhyperemic pressure ratios are affected by hemodynamic interdependence. When the functional significance of serial coronary stenoses is severe, the effect is similar to that which is seen with FFR.

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.)

Background: The treatment of a coronary bifurcation with a single stent (the provisional stenting technique) is associated with a good outcome in most cases. In the majority of cases, after provisional stenting technique, a residual significant angiographic stenosis is associated with the absence of ischemia when fractional flow reserve (FFR) is measured. Jailing an optical pressure guidewire in the side branch (SB) could potentially reduce unnecessary SB interventions after provisional stenting technique. The aim of this study was to compare distal pressure to aortic pressure ratio (Pd/Pa) measurements between 2 second-generation optical pressure guidewires in bifurcation treatment-a jailed wire (JW) and a second free-floating wire (FW) advanced into the SB after stenting., Methods: In an in vitro bifurcation hydrodynamic model with pressure sensors, a JW was advanced into the SB and the FW into the main branch. Bifurcation stenting is performed with the proximal optimization technique (POT)-side-POT technique using a 3.0 x 22-mm stent, a 4.0 x 12-mm noncompliant balloon for the POT, and a 2.5 x 12-mm semicompliant balloon for the SB opening. The same steps were performed in a second model where a surgical clamp was placed in the main vessel to lower overall absolute values pressures., Results: A strong correlation was found between JW and FW values (Pearson's coefficient, r=0.91). All wires could be safely retrieved., Conclusion: In bifurcation stenting, the Pd/Pa value of a second-generation optical pressure guidewire jailed in the SB is reliable compared with a FW inserted after stent implantation.

Objectives: It is unknown whether computed tomographic coronary angiography (CTCA) can be used to perform ultraselective invasive coronary angiography (ICA) by only visualizing the abnormal coronary artery on CTCA and defer visualization of the normal contralateral coronary artery. This study assessed the accuracy of CTCA in patients with coronary artery disease (CAD) on CTCA limited to either the left (LCA) or right coronary artery (RCA) in predicting a contralateral coronary artery without abnormalities on CTCA determined to be normal by ICA., Methods: This retrospective analysis included patients with CAD limited to the LCA or RCA on CTCA. Primary endpoint was the accuracy of CTCA to predict a contralateral coronary artery without abnormalities on CTCA to be normal by ICA. Secondary endpoints were potential reductions in procedure time and radiation exposure if an ultraselective ICA approach would be used compared to standard ICA., Results: In total, 202 patients were included. CTCA was correct in predicting a normal contralateral coronary artery in 201 of the 202 patients (99.5%). Deferring ICA of the normal contralateral coronary artery on CTCA resulted in a potential reduction in procedure time and dose area product of 4.22 ± 2.67 minutes (61 ± 16% reduction) and 1501 ± 1304 mGy•cm² (29 ± 13% reduction)., Conclusions: In this retrospective study, CTCA was extremely accurate in predicting a normal contralateral coronary artery in patients with LCA- or RCA-limited CAD on CTCA. A potential CTCA-guided ultraselective ICA approach was feasible and would have led to a considerable decrease in procedure time and radiation exposure.

The need for a quantitative and operator-independent assessment of coronary microvascular function is increasingly recognized. We propose the theoretical framework of microvascular resistance reserve (MRR) as an index specific for the microvasculature, independent of autoregulation and myocardial mass, and based on operator-independent measurements of absolute values of coronary flow and pressure. In its general form, MRR equals coronary flow reserve (CFR) divided by fractional flow reserve (FFR) corrected for driving pressures. In 30 arteries, pressure, temperature, and flow velocity measurements were obtained simultaneously at baseline (BL), during infusion of saline at 10 mL/min (rest) and 20 mL/min (hyperemia). A strong correlation was found between continuous thermodilution-derived MRR and Doppler MRR (r = 0.88; 95% confidence interval: 0.72-0.93; P < 0.001). MRR was independent from the epicardial resistance, the lower the FFR value, the greater the difference between MRR and CFR. Therefore, MRR is proposed as a specific, quantitative, and operator-independent metric to quantify coronary microvascular dysfunction., Competing Interests: Funding Support and Author Disclosures Dr De Bruyne has had a consulting relationship with Boston Scientific, Abbott Vascular, CathWorks, Siemens, and Coroventis Research; has received research grants from Abbott Vascular, Coroventis Research, Cathworks, and Boston Scientific; and holds minor equities in Philips-Volcano, Siemens, GE Healthcare, Edwards Life Sciences, HeartFlow, Opsens, and Celiad. Dr Pijls has received institutional grants from Abbott Vascular and Hexacath; has served as a consultant for Abbott Vascular, GE, and Opsens; and has minor equities in Philips, GE, ASML, and HeartFlow. Dr Collet has received research grants from Biosensor, GE Healthcare, Medis Medical Imaging, Pie Medical Imaging, Cathworks, Boston Scientific, Siemens, HeartFlow Inc, and Abbott Vascular; and has received consultancy fees from Heart Flow Inc, Opsens, Pie Medical Imaging, Abbott Vascular, and Philips-Volcano. Dr Barbato has received speaker’s fees from Abbott Vascular, Boston Scientific, and GE. Dr Fearon has received institutional research support from Abbott Vascular, Medtronic, and Edwards Lifesciences; has had a consulting relationship with CathWorks; and holds minor stock options with HeartFlow. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021. Published by Elsevier Inc.)

Objectives: Performing percutaneous coronary intervention (PCI) for fractional flow reserve (FFR) positive coronary lesions improves clinical outcomes and is recommended by international guidelines. It has been hypothesized that lesions with a positive FFR but a preserved coronary flow reserve (CFR) are less likely to be flow limiting and might best be treated medically. We investigated the association of CFR in FFR-positive lesions with clinical outcomes when treated medically, as well as the treatment effect of PCI vs medical therapy in FFR-positive lesions and a preserved CFR., Methods: We performed a substudy of the randomized, multicenter Compare-Acute trial, in which stabilized ST-segment elevation myocardial infarction (STEMI) patients with non-culprit lesions were randomized to either FFR-guided PCI or medical therapy. Based on baseline and hyperemic pressure gradients, we computed physiologic limits of CFR, the so-called pressure-bounded CFR (pb-CFR), and classified lesions as low (<2) or preserved (≥2). The primary endpoint was 12-month major adverse cardiac and cerebrovascular event (MACCE) rate, defined as a composite of death from any cause, non-fatal myocardial infarction, revascularization, or cerebrovascular events., Results: A total of 980 lesions from 885 patients were included in this substudy. In lesions with FFR ≤0.80, a total of 249 patients had a pb-CFR <2 and 29 patients had a preserved CFR (pb-CFR ≥2). The rate of MACCE at 1 year was not significantly different between patients with FFR ≤0.80 and pb-CFR <2 vs patients with FFR ≤0.80 and pb-CFR ≥2 (25% vs 17%, respectively; P=.39). Because of randomization, baseline characteristics were well balanced between patients with FFR ≤0.80 and pb-CFR ≥2 treated by either by PCI or medical therapy. Importantly, in patients with FFR ≤0.80 and pb-CFR ≥2, MACCE occurred more frequently in patients treated medically vs patients treated by PCI (44% vs 0%, respectively; P=.01)., Conclusions: Preserved or low pb-CFR did not alter clinical outcomes in patients with a positive FFR. Patients with FFR-positive coronary lesions but a preserved CFR had more clinical events when treated medically vs those treated with PCI.

Background: Invasive functional assessment is a mainstay in the management of patients with coronary artery disease (CAD), but there is uncertainty on the comparative accuracy of diagnostic indices of functional significance. We aimed to validate the diagnostic performance of a novel non-hyperemic diastolic pressure ratio (dPR)., Methods: We performed a retrospective analysis including two separate registries (VERIFY 2, Latina, Italy) of patients in whom functional indices were measured for lesions with angiographically moderate severity. On top of fractional flow reserve, distal coronary pressure (Pd)/aortic pressure (Pa) ratio, instantaneous wave-free ratio (iFR) and diastolic pressure ratio (dPR) were computed using a novel dedicated algorithm over 4 consecutive beats. Agreement/discrepancy between indexes was appraised Bland-Altman analysis, area under the receiver operating characteristic curve (AUC), and unsupervised machine learning., Results: A total of 525 lesions from 479 patients were included. The novel dPR was highly correlated with iFR (R 2 =0.99, P<0.001), with a mean difference of -0.004±0.014. The diagnostic performance of dPR (best cutoff value: ≤0.89) against iFR was as follows: accuracy =96%; sensitivity =94%; specificity =97%; positive-predictive value =94%; and negative-predictive value =96%. Additionally, AUC to predict iFR≤0.89 was 0.99, which was significantly higher than that of Pd/Pa (0.97, P<0.001). In the iFR range of 0.85-0.93 ("grey zone"), the diagnostic performance was well maintained (accuracy =91%; sensitivity =87%; specificity =93%; and AUC=0.96). Results were supported also by unsupervised learning analysis., Conclusions: This multicenter registry suggests this novel dPR algorithm provides results that are numerically equivalent to iFR. Pending further studies, physicians may consider using this novel dPR algorithm to gauge the functional significance of a coronary lesion.

During the last two decades, there has been a sharp increase in both interest and knowledge about the coronary microcirculation. Since these small vessels are not visible by the human eye, physiologic measurements should be used to characterize their function. The invasive methods presently used (coronary flow reserve (CFR) and index of microvascular resistance (IMR)) are operator-dependent and mandate the use of adenosine to induce hyperemia. In recent years, a new thermodilution-based method for measurement of absolute coronary blood flow and microvascular resistance has been proposed and initial procedural problems have been overcome. Presently, the technique is easy to perform using the Rayflow infusion catheter and the Coroventis software. The method is accurate, reproducible, and completely operator-independent. This method has been validated noninvasively against the current golden standard for flow assessment: Positron Emission Tomography-Computed Tomography (PET-CT). In addition, absolute flow and resistance measurements have proved to be safe, both periprocedurally and at long-term follow-up. With an increasing number of studies being performed, this method has great potential for better understanding and quantification of microvascular disease., Competing Interests: Nico H. J. Pijls reports institutional grant from Abbott and Hexacath, consulting for Abbott and Opsens, minor equities in Philips, GE, ASML, and Heartflow, and consulting for GE and personal fees for GE. All other authors report no conflicts of interest., (Copyright © 2020 Daniëlle C. J. Keulards et al.)

Background This study aimed to investigate longitudinal physiological changes in the recanalized coronary chronic total occlusion (CTO) vessel and its dependent myocardium after successful percutaneous coronary intervention (PCI). Methods and Results In this pilot study, 25 patients scheduled for elective CTO PCI with viable myocardium and angiographically visible collaterals were included. Absolute coronary blood flow and absolute microvascular resistance were measured invasively using continuous thermodilution. Measurements were performed immediately after successful CTO PCI and at short-term follow-up. In a subgroup of patients, physiological measurements were performed at the predominant donor vessel before CTO PCI, immediately afterwards, and at follow-up. Absolute coronary blood flow in the recanalized CTO artery increased from 148±53 mL/min immediately after PCI to 221±77 mL/min at follow-up ( P <0.001). In agreement, absolute resistance in the myocardial territory perfused by the CTO artery, decreased from 545±255 Wood units immediately after the procedure to 387±128 Wood units at follow-up ( P =0.014). There were no significant changes in the absolute coronary blood flow and resistance in the predominant donor between baseline and follow-up. Positive remodeling of the distal CTO vessel with an increase in lumen diameter was observed. Conclusions After successful CTO PCI, blood flow in the recanalized artery and microvascular function of the dependent myocardium are not immediately normal but recover over time.

Aims: Several invasive techniques are available in clinical practice to assess coronary flow. Nevertheless, the test-retest repeatability of these techniques in a controlled setting has not been reported. Therefore, we sought to evaluate fractional flow reserve (FFR), coronary flow reserve (CFR), index of microvascular resistance (IMR), and absolute coronary blood flow (ABF) with absolute microvascular resistance (AMR) test-retest repeatability using a coronary flow simulator., Methods and Results: Using a coronary flow simulator (FFR WetLab version 2.0; Abbott Vascular, Santa Clara, CA), we created stenoses ranging from 0% to 70%, with 10% increments. Three different flows were established with their hyperemic phases, and two consecutive measurements were obtained, evaluating the following indices: FFR, CFR, IMR, ABF, and AMR, using a pressure/temperature wire and an infusion catheter. One hundred and thirty-eight pairs of measurements were performed. Test-retest reliability was compared in 48 FFR, 18 CFR, 24 IMR, 24 ABF, and 24 AMR. Test-retest repeatability showed excellent reproducibility for FFR, ABF, and AMR; respectively 0.98 (0.97-0.99), 0.92 (0.81-0.97) and 0.91 (0.79-0.96) (P < 0.0001 for all). However, test-retest repeatability was weaker for IMR and poor for CFR; respectively 0.53 (0.16-0.77) (P = 0.006) and 0.27 (-0.26-0.67) (P = 0.30)., Conclusions: Using a coronary flow simulator, FFR and ABF with AMR had excellent test-retest reliability. IMR and CFR demonstrated weaker test-retest reliability., (© 2019 Wiley Periodicals, Inc.)

Background: The principle of continuous thermodilution can be used to calculate absolute coronary blood flow and microvascular resistance (R). The aim of the study is to explore the safety, feasibility, and reproducibility of coronary blood flow and R measurements as measured by continuous thermodilution in humans., Methods and Results: Absolute coronary flow and R can be calculated by thermodilution by infusing saline at room temperature through a dedicated monorail catheter. The temperature of saline as it enters the vessel, the temperature of blood and saline mixed in the distal part of the vessel, and the distal coronary pressure were measured by a pressure/temperature sensor-tipped guidewire. The feasibility and safety of the method were tested in 135 patients who were referred for coronary angiography. No significant adverse events were observed; in 11 (8.1%) patients, bradycardia and concomitant atrioventricular block appeared transiently and were reversed immediately on interruption of the infusion. The reproducibility of measurements was tested in a subgroup of 80 patients (129 arteries). Duplicate measurements had a strong correlation both for coronary blood flow (ρ=0.841, P <0.001; intraclass correlation coefficient=0.89, P <0.001) and R (ρ=0.780, P <0.001; intraclass correlation coefficient=0.89, P <0.001). In Bland-Altman plots, there was no significant bias or asymmetry., Conclusions: Absolute coronary blood flow (in L/min) and R (in mm Hg/L/min or Wood units) can be safely and reproducibly measured with continuous thermodilution. This approach constitutes a new opportunity for the study of the coronary microcirculation., (© 2018 American Heart Association, Inc.)

Background: Pressure measurement for the duration of the wave-free period (WFP) is considered essential for resting-state physiological assessment of coronary stenosis severity using the instantaneous wave-free ratio (iFR)., Objectives: The aim of this study was to compare other diastolic resting indexes to iFR., Methods: In the population of the VERIFY2 (Pd/Pa vs iFR in an Unselected Population Referred for Invasive Angiography) study, iFR calculated by proprietary software (Volcano Harvest, Volcano Corporation, Rancho Cordova, California) was compared with the ratio of resting distal coronary pressure and aortic pressure during the complete duration of diastole (dPR), 25% to 75% of diastole (dPR 25-75 ), and midpoint of diastole (dPR mid ), along with Matlab calculated iFR (iFR matlab ) and iFR-like indexes shortening the length of the WFP by 50 and 100 ms (iFR -50ms and iFR -100ms ), respectively. Mutual differences, Spearman correlations, area under the curve values from receiver-operating characteristic analyses, and diagnostic performance with respect to iFR and fractional flow reserve (FFR) were calculated for all indexes., Results: Median iFR in 197 patients with 257 vessels was 0.91 with an interquartile range of 0.87 to 0.95. The mutual differences (± SD) with iFR were 0.006 ± 0.011 (dPR), 0.001 ± 0.007 (dPR 25-75 ), 0.001 ± 0.008 (dPR mid ), 0.005 ± 0.009 (iFR matlab ), 0.003 ± 0.008 (iFR -50ms ), and 0.001 ± 0.009 (iFR -100ms ). Correlations for all indexes with iFR were >0.99 (p < 0.001 for all). Area under the curve values for predicting iFR were >0.99 for all indexes as well. Diagnostic accuracy compared with FFR was 76% to 77% for all indexes including iFR., Conclusions: All diastolic resting indexes tested were identical to iFR, both numerically and with respect to their agreement with FFR. A numerically equal value to iFR can be determined without restriction to the WFP. Cutoff values, guidelines, and clinical recommendations for iFR can therefore be extended to these other indexes. (Pd/Pa vs iFR in an Unselected Population Referred for Invasive Angiography [VERIFY2]; NCT02377310)., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: In ST-elevation myocardial infarction (STEMI), reduction in time to reperfusion of the occluded coronary artery reduces infarct size. In animal models, an additional reduction of infarct size was observed when hypothermia was induced before reperfusion, despite a longer ischemic time. However, several human studies did not corroborate this positive effect, which is believed to be in part due to the inability of systemic induced hypothermia to induce sufficient decrease of local myocardial temperature before reperfusion. Providing rapid local myocardial hypothermia by intracoronary infusion of saline before reperfusion in patients with STEMI may overcome this problem. In this study, we evaluate the safety and feasibility of providing rapid intracoronary myocardial hypothermia in patients undergoing intracoronary blood flow measurements based on thermodilution with continuous infusion of saline at room temperature., Methods and Results: In 53 patients with stable angina (SA) and 20 patients with STEMI, a total of 215 measurements were performed. The measurements consisted of continuous selective intracoronary infusion of saline at room temperature with rates between 10 ml/min and 30 ml/min. Temperature changes compared to initial blood temperature (Tb ) were measured at the tip of the infusion catheter (Ti ) and distally in the coronary artery (Td ). In patients with SA, Ti was -5.65 ± 1.41°C (range -9.27 to -2.28) and Td was -0.78 ± 0.51°C (range -3.27 to -0.23°C). In patients with STEMI, Ti was -7.45 ± 0.51°C (range -8.21 to -6.56) and Td was -1.37 ± 0.82°C (range -4.62 to -0.74°C). In all patients, steady-state intracoronary hypothermia was achieved within 15 sec and could be maintained without noticeable complications., Conclusion: This study demonstrates the safety and feasibility of inducing intracoronary hypothermia by selective infusion of saline at room temperature in patients with SA and STEMI. Steady-state hypothermia could be achieved and maintained quickly, easily, and safely using common PCI techniques. Therefore, our findings warrant further studies to the use of intracoronary hypothermia to enhance myocardial salvage in acute myocardial infarction., (© 2015 Wiley Periodicals, Inc.)

Background: In the Fractional Flow Reserve Versus Angiography for Multivessel Evaluation (FAME) study, fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) improved outcome compared with angiography-guided PCI for up to 2 years of follow-up. The aim in this study was to investigate whether the favourable clinical outcome with the FFR-guided PCI in the FAME study persisted over a 5-year follow-up., Methods: The FAME study was a multicentre trial done in Belgium, Denmark, Germany, the Netherlands, Sweden, the UK, and the USA. Patients (aged ≥ 18 years) with multivessel coronary artery disease were randomly assigned to undergo angiography-guided PCI or FFR-guided PCI. Before randomisation, stenoses requiring PCI were identified on the angiogram. Patients allocated to angiography-guided PCI had revascularisation of all identified stenoses. Patients allocated to FFR-guided PCI had FFR measurements of all stenotic arteries and PCI was done only if FFR was 0·80 or less. No one was masked to treatment assignment. The primary endpoint was major adverse cardiac events at 1 year, and the data for the 5-year follow-up are reported here. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00267774., Findings: After 5 years, major adverse cardiac events occurred in 31% of patients (154 of 496) in the angiography-guided group versus 28% (143 of 509 patients) in the FFR-guided group (relative risk 0·91, 95% CI 0·75-1·10; p=0·31). The number of stents placed per patient was significantly higher in the angiography-guided group than in the FFR-guided group (mean 2·7 [SD 1·2] vs 1·9 [1·3], p<0·0001)., Interpretation: The results confirm the long-term safety of FFR-guided PCI in patients with multivessel disease. A strategy of FFR-guided PCI resulted in a significant decrease of major adverse cardiac events for up to 2 years after the index procedure. From 2 years to 5 years, the risks for both groups developed similarly. This clinical outcome in the FFR-guided group was achieved with a lower number of stented arteries and less resource use. These results indicate that FFR guidance of multivessel PCI should be the standard of care in most patients., Funding: St Jude Medical, Friends of the Heart Foundation, and Medtronic., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Introduction The aim of this study was to compare magnetic resonance angiography (MRA) with digital subtraction angiography (DSA) in the preoperative assessment of crural arteries and their skin perforators prior to free fibular transfer. Patients and methods Fifteen consecutive patients, scheduled for free vascularized fibular flap transfer, were subjected to DSA as well as MRA of the crural arteries of both legs (n = 30). All DSA and MRA images were assessed randomly, blindly, and independently by two radiologists. Each of the assessors scored the degree of stenosis of various segments on a 5 point scale from 0 (occlusive) to 4 (no stenosis). The Cohen's Kappa coefficient was used to assess the agreement between DSA and MRA scores. In addition, the number of cutaneous perforators were scored and the assessors were asked if they would advise against fibula harvest and transplantation based on the images. Results A Cohen's Kappa of 0.64, indicating "substantial agreement of stenosis severity scores" was found between the two imaging techniques. The sensitivity of MRA to detect a stenosis compared with DSA was 79% (CI 95%:60-91), and a specificity of 98% (CI 95%: 97-99). In 53 out of 60 assessments, advice on suitability for transfer were equal between DSA and MRA. The median number of cutaneous perforators that perfuse the skin overlying the fibula per leg was one for DSA as well as MRA (P = 0.142).Conclusions A substantial agreement in the assessment of stenosis severity was found between DSA and MRA. The results suggest that MRA is a good alternative to DSA in the preoperative planning of free fibula flap transplantation., (Copyright © 2013 Wiley Periodicals, Inc.)

Measurement of coronary pressure and absolute flow dynamics have shown great potential in discerning different types of coronary circulatory disease. In the present study, the feasibility of assessing pressure and flow dynamics with a combination of two thermal methods, developed in combination with a pressure-sensor-tipped guide wire, was evaluated in an in vitro coronary model. A continuous infusion thermodilution method was employed to determine the average flow, whereas a thermal anemometric method was utilized to assess the pressure and flow dynamics, simultaneously. In the latter method, the electrical power supplied to an element, kept at constant temperature above ambient temperature, was used as a measure for the shear rate. It was found that, using a single calibration function, the method was able to assess coronary pressure and flow dynamics for different flow amplitudes, heart rates, and different pressure wires. However, due to the fact that the thermal anemometric method cannot detect local shear rate reversal, the method was unable to reliably measure flow dynamics close to zero. Nevertheless, the combined methodology was able to reliably assess diastolic hemodynamics. The diastolic peak flow and average diastolic resistance could be determined with a small relative error of (8 ± 7)% and (7 ± 5)%, respectively., (Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.)

A model describing the primary relations between the cardiac muscle and coronary circulation might be useful for interpreting coronary hemodynamics in case multiple types of coronary circulatory disease are present. The main contribution of the present study is the coupling of a microstructure-based heart contraction model with a 1D wave propagation model. The 1D representation of the vessels enables patient-specific modeling of the arteries and/or can serve as boundary conditions for detailed 3D models, while the heart model enables the simulation of cardiac disease, with physiology-based parameter changes. Here, the different components of the model are explained and the ability of the model to describe coronary hemodynamics in health and disease is evaluated. Two disease types are modeled: coronary epicardial stenoses and left ventricular hypertrophy with an aortic valve stenosis. In all simulations (healthy and diseased), the dynamics of pressure and flow qualitatively agreed with observations described in literature. We conclude that the model adequately can predict coronary hemodynamics in both normal and diseased state based on patient-specific clinical data.

Objectives: The aim of this study was to assess the validity of measuring fractional flow reserve (FFR) of the left main (LM) coronary artery in the setting of concomitant left anterior descending (LAD) or left circumflex (LCX) stenoses., Background: The theoretical impact of a stenosis in the LAD on the FFR assessment of intermediate LM disease with the pressure wire in an unobstructed LCX is currently unknown., Methods: A previously validated in vitro model of the coronary circulation was used to create a fixed intermediate stenosis of the LM and a variable downstream LAD or LCX stenosis. The true LM FFR (FFR(LM true)), with no concomitant downstream disease, was compared to the apparent LM FFR (FFR(LM apparent)), with concomitant downstream disease measured with different degrees of LAD or LCX disease. Additionally, an equation based on a resistors model was derived to predict the effect of downstream stenosis on LM FFR (FFR(LM predicted))., Results: In the setting of isolated moderate LM disease (FFR 0.72 ± 0.08), mild to moderate proximal LAD or LCX lesions did not significantly affect LM FFR. Lesions with a composite FFR (LM + downstream disease) ≥0.65 resulted in an FFR(LM apparent) that was not significantly different from FFR(LM true) (0.76 ± 0.06 vs. 0.76 ± 0.05, p = 0.124). Our equation for FFR(LM predicted) accurately modeled the effects of concomitant disease (r = 0.95, p < 0.001)., Conclusions: These data suggest that in the presence of proximal mild to moderate LAD or LCX disease, LM FFR can be reliably measured with the pressure wire placed in the uninvolved epicardial artery., (Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: The aim of this study was to study whether there is a difference in benefit of fractional flow reserve (FFR) guidance for percutaneous coronary intervention (PCI) in multivessel coronary disease in patients with unstable angina (UA) or non-ST-segment elevation myocardial infarction (NSTEMI), compared with stable angina (SA)., Background: The use of FFR to guide PCI has been well established for patients with SA. Its use in patients with UA or NSTEMI has not been investigated prospectively., Methods: In the FAME (Fractional flow reserve versus Angiography for Multivessel Evaluation) study 1,005 patients with multivessel disease amenable to PCI were included and randomized to either angiography-guided PCI of all lesions ≥50% or FFR-guided PCI of lesions with an FFR ≤0.80. Patients admitted for UA or NSTEMI with positive troponin but total creatine kinase <1,000 U/l were eligible for inclusion. We determined 2-year major adverse cardiac event rates of these patients and compared it with stable patients., Results: Of 1,005 patients, 328 had UA or NSTEMI. There was no evidence for heterogeneity among the subgroups for any of the outcome variables (all p values >0.05). Using FFR to guide PCI resulted in similar risk reductions of major adverse cardiac events and its components in patients with UA or NSTEMI, compared with patients with SA (absolute risk reduction of 5.1% vs. 3.7%, respectively, p = 0.92). In patients with UA or NSTEMI, the number of stents was reduced without increase in hospital stay or procedure time and with less contrast use, in similarity to stable patients., Conclusions: The benefit of using FFR to guide PCI in multivessel disease does not differ between patients with UA or NSTEMI, compared with patients with SA., (Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

The Impella 2.5 left percutaneous (LP), a relatively new transvalvular assist device, challenges the position of the intra-aortic balloon pump (IABP), which has a long record in supporting patients after myocardial infarction and cardiac surgery. However, while more costly and more demanding in management, the advantages of the Impella 2.5 LP are yet to be established. The aim of this study was to evaluate the benefits of the 40 cc IABP and the Impella 2.5 LP operating at 47,000 rpm in vitro, and compare their circulatory support capabilities in terms of cardiac output, coronary flow, cardiac stroke work, and arterial blood pressure. Clinical scenarios of cardiogenic preshock and cardiogenic shock (CS), with blood pressure depression, lowered cardiac output, and constant heart rate of 80 bpm, were modeled in a model-controlled mock circulation, featuring a systemic, pulmonary, and coronary vascular bed. The ventricles, represented by servomotor-operated piston pumps, included the Frank-Starling mechanism. The systemic circulation was modeled with a flexible tube having close-to-human aortic dimensions and compliance properties. Proximally, it featured a branch mimicking the brachiocephalic arteries and a physiological correct coronary flow model. The rest of the systemic and pulmonary impedance was modeled by four-element Windkessel models. In this system, the enhancement of coronary flow and blood pressure was tested with both support systems under healthy and pathological conditions. Hemodynamic differences between the IABP and the Impella 2.5 LP were small. In our laboratory model, both systems approximately yielded a 10% cardiac output increase and a 10% coronary flow increase. However, since the Impella 2.5 LP provided significantly better left ventricular unloading, the circulatory support capabilities were slightly in favor of the Impella 2.5 LP. On the other hand, pulsatility was enhanced with the IABP and lowered with the Impella 2.5 LP. The support capabilities of both the IABP and the Impella 2.5 LP strongly depended on the simulated hemodynamic conditions. Maximum hemodynamic benefits were achieved when mechanical circulatory support was applied on a simulated scenario of deep CS., (© 2011, Copyright Eindhoven University of Technology (TU/e). Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

Rapid identification and treatment of patients with a myocardial infarction (MI) is mandatory. We studied the diagnostic capacities of a sensitive troponin assay for detection of MI in emergency department patients within 2 hours after arrival. The study included 157 patients suspected of having non-ST-elevation acute coronary syndrome. Blood was drawn on arrival (T0) and 2 (T2), 6, and 12 hours later. At T2, a troponin concentration above the MI cutoff is 87% sensitive and 100% specific for MI detection (positive predictive value [PPV], 100%; negative predictive value [NPV], 96%). If a difference of more than 30% between the troponin measurements at T0 and T2 in the absence of an absolute troponin increase above the 99th percentile of a reference population is also considered indicative of MI, the sensitivity increases to 100% and specificity decreases to 87% (PPV, 70%; NPV, 100%). Sensitivity and specificity of creatine kinase-MB and myoglobin are lower than those of troponin. By using a sensitive troponin assay and simple algorithms, the diagnosis of MI can be determined within 2 hours after arrival at the emergency department. Measurement of myoglobin and creatine kinase-MB has no added value.

Objectives: The purpose of this study was to investigate the 2-year outcome of percutaneous coronary intervention (PCI) guided by fractional flow reserve (FFR) in patients with multivessel coronary artery disease (CAD)., Background: In patients with multivessel CAD undergoing PCI, coronary angiography is the standard method for guiding stent placement. The FAME (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation) study showed that routine FFR in addition to angiography improves outcomes of PCI at 1 year. It is unknown if these favorable results are maintained at 2 years of follow-up., Methods: At 20 U.S. and European medical centers, 1,005 patients with multivessel CAD were randomly assigned to PCI with drug-eluting stents guided by angiography alone or guided by FFR measurements. Before randomization, lesions requiring PCI were identified based on their angiographic appearance. Patients randomized to angiography-guided PCI underwent stenting of all indicated lesions, whereas those randomized to FFR-guided PCI underwent stenting of indicated lesions only if the FFR was 0.80, the rate of myocardial infarction was 0.2% and the rate of revascularization was 3.2 % after 2 years., Conclusions: Routine measurement of FFR in patients with multivessel CAD undergoing PCI with drug-eluting stents significantly reduces mortality and myocardial infarction at 2 years when compared with standard angiography-guided PCI. (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation [FAME]; NCT00267774)., (Copyright (c) 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: The purpose of this study was to investigate the relationship between angiographic and functional severity of coronary artery stenoses in the FAME (Fractional Flow Reserve Versus Angiography in Multivessel Evaluation) study., Background: It can be difficult to determine on the coronary angiogram which lesions cause ischemia. Revascularization of coronary stenoses that induce ischemia improves a patient's functional status and outcome. For stenoses that do not induce ischemia, however, the benefit of revascularization is less clear., Methods: In the FAME study, routine measurement of the fractional flow reserve (FFR) was compared with angiography for guiding percutaneous coronary intervention in patients with multivessel coronary artery disease. The use of the FFR in addition to angiography significantly reduced the rate of all major adverse cardiac events at 1 year. Of the 1,414 lesions (509 patients) in the FFR-guided arm of the FAME study, 1,329 were successfully assessed by the FFR and are included in this analysis., Results: Before FFR measurement, these lesions were categorized into 50% to 70% (47% of all lesions), 71% to 90% (39% of all lesions), and 91% to 99% (15% of all lesions) diameter stenosis by visual assessment. In the category 50% to 70% stenosis, 35% were functionally significant (FFR 0.80). In the category 71% to 90% stenosis, 80% were functionally significant and 20% were not. In the category of subtotal stenoses, 96% were functionally significant. Of all 509 patients with angiographically defined multivessel disease, only 235 (46%) had functional multivessel disease (>or=2 coronary arteries with an FFR

Direct volumetric assessment of coronary flow during cardiac catheterization has not been available so far. In the current study continuous infusion thermodilution, a method based on continuous infusion of saline into a selective coronary artery is evaluated. Theoretically, volumetric flow can be calculated from the known infusion rate (Q(i)), the temperatures of the blood (T(b)), the saline (T(i)), and the mixture downstream to the infusion site (T). We aimed to validate and optimize the measurement method in an in vitro model of the coronary circulation. Full mixing of infusate and blood was found to be the main prerequisite for accurate determination of the coronary flow. To achieve full mixing the influence of catheter design, infusion rate, and location of temperature measurement were assessed. We found that continuous infusion thermodilution slightly overestimated coronary flow determined by directly measured reference flow by 7+/-8%, over the entire physiological flow range of 50-250 ml/min. These results were found using a specially designed infusion catheter (infusion mainly through distally located sideholes), a high enough infusion rate (25 ml/min), and measurement of the mixing temperature between 5 and 8 cm distal from the tip of the infusion catheter. Absolute coronary flow rate can be measured reliably by the continuous infusion method when full mixing is present, under the conditions mentioned above.

Objectives: This study sought to validate a new method for direct volumetric blood flow measurement in coronary arteries in animals and in conscious humans during cardiac catheterization., Background: Direct volumetric measurement of blood flow in selective coronary arteries would be useful for studying the coronary circulation., Methods: Based on the principle of thermodilution with continuous low-rate infusion of saline at room temperature, we designed an instrumental setup for direct flow measurement during cardiac catheterization. A 2.8-F infusion catheter and a standard 0.014-inch sensor-tipped pressure/temperature guidewire were used to calculate absolute flow (Q(thermo)) in a coronary artery from the infusion rate of saline, temperature of the saline at the tip of the infusion catheter, and distal blood temperature during infusion. The method was tested over a wide range of flow rates in 5 chronically instrumented dogs and in 35 patients referred for physiological assessment of a coronary stenosis or for percutaneous coronary intervention., Results: Thermodilution-derived flow corresponded well with true flow (Q) in all dogs (Q(thermo) = 0.73 Q + 42 ml/min; R(2) = 0.72). Reproducibility was excellent (Q(thermo,)(1) = 0.96 x Q(thermo,)(2) + 3 ml/min; R(2) = 0.89). The measurements were independent of infusion rate and sensor position as predicted by theory. In the humans, a good agreement was found between increase of thermodilution-derived volumetric blood flow after percutaneous coronary intervention and increase of fractional flow reserve (R(2) = 0.84); reproducibility of the measurements was excellent (Q(thermo,)(1) = 1.0 Q(thermo,)(2) + 0.9 ml/min, R(2) = 0.97), and the measurements were independent of infusion rate and sensor position., Conclusions: Using a suitable infusion catheter and a 0.014-inch sensor-tipped guidewire for measurement of coronary pressure and temperature, volumetric blood flow can be directly measured in selective coronary arteries during cardiac catheterization.

Objectives: The objective of this study was to investigate the underlying stenosis severity of the culprit lesion in acute myocardial infarction., Background: It is widely believed that myocardial infarction often occurs in angiographically mild luminal stenosis. This, however, is in contradiction with experience from interventional practice in primary PCI., Methods: We performed quantitative coronary angiography (QCA) in 250 consecutive patients referred for acute percutaneous coronary intervention (PCI) because of acute myocardial infarction (AMI). Fundamental for analysis was that a realistic estimate of underlying luminal narrowing before the infarction could be made angiographically that QCA could be performed and that one of two criteria was met: (1) spontaneous reflow allowing assessment of the lumen proximal and distal to the culprit lesion, or (2) coronary artery closed at arrival but reflow after uncomplicated wiring allowing assessment of the lumen proximal and distal to the culprit lesion., Results: Of 250 consecutive patients (mean age 61.7 +/- 12.7 years, 48 women) referred for acute PCI, 156 patients (62%) fulfilled at least one of the above criteria for reliable QCA. In 151 of these patients (96%) the severity of the underlying stenosis was >50% and in 103 (66%) it was >70%. There were no differences in stenosis severity between the left anterior descending [LAD, (72 +/- 13)%, n = 57], left circumflex [Cx, (74 +/- 10)%, n = 20], and right coronary artery territory [RCA, (74 +/- 12)%, n = 76] (ANOVA, P = 0.76). There were no differences in stenosis severity between women [(73 +/- 13)%, n = 36] and men [(75 +/- 11)%, n = 120; P = 0.35]., Conclusion: In contrast to what is often believed, the majority of myocardial infarctions occurs in significant stenosis., (Copyright 2007 Wiley-Liss, Inc.)

Orientation of a bi-leaflet prosthesis (BLP) might influence coronary perfusion. The aim of this study was to investigate the influence of the orientation on coronary perfusion pressure during hyperemia and adrenergic stimulation. During hyperemia perfusion pressure determines coronary blood flow. Fourteen patients with normal coronary angiogram underwent aortic valve replacement (AVR) by a BLP, and seven received a bio-prosthesis. Patients receiving a BLP were randomized to either orientation A (hinge mechanism perpendicular to a line drawn between the coronary ostia) or B (hinge mechanism parallel to the line between the ostia). Six months after surgery all patients underwent cardiac catheterization. Pressures were measured during resting conditions, during maximum hyperemia, and during maximum adrenergic stimulation with a guiding catheter in the aortic arch (P(ao)), simultaneously with a sensor tipped guide wire in the coronary artery (P(cor)) and in the aortic root (P(root)). P(ao)-P(root) described a flow-induced pressure drop in the aortic root (Venturi effect) and the gradient P(root)-P(cor) described coronary ostium abnormalities. Only small non-significant differences in myocardial perfusion pressure were found between different orientations of a bi-leaflet prosthesis or between bi-leaflet prostheses and bio-prostheses in P(ao)-P(root) and P(root)-P(cor).

Objectives: The purpose of this study was to investigate the appropriateness of stenting a functionally nonsignificant stenosis., Background: Percutaneous coronary intervention (PCI) of an intermediate stenosis without evidence of ischemia is often performed, but its benefit is unproven. Coronary pressure-derived fractional flow reserve (FFR) is an invasive index used to identify a stenosis responsible for reversible ischemia., Methods: In 325 patients scheduled for PCI of an intermediate stenosis, FFR was measured just before the planned intervention. If FFR was >or =0.75, patients were randomly assigned to deferral (Defer group; n = 91) or performance (Perform group; n = 90) of PCI. If FFR was <0.75, PCI was performed as planned (Reference group; n = 144). Clinical follow-up was 5 years., Results: There were no differences in baseline clinical characteristics between the 3 groups. Complete follow-up was obtained in 98% of the patients. Event-free survival was not different between the Defer and Perform groups (80% and 73%, respectively; p = 0.52), but was significantly worse in the Reference group (63%; p = 0.03). The composite rate of cardiac death and acute myocardial infarction in the Defer, Perform, and Reference groups was 3.3%, 7.9%, and 15.7%, respectively (p = 0.21 for Defer vs. Perform group; p = 0.003 for the Reference vs. both other groups). The percentage of patients free from chest pain at follow-up was not different between the Defer and Perform groups., Conclusions: Five-year outcome after deferral of PCI of an intermediate coronary stenosis based on FFR >/=0.75 is excellent. The risk of cardiac death or myocardial infarction related to this stenosis is <1% per year and not decreased by stenting.

Aims: The aim of this study was to investigate the physiologic parameters: fractional flow reserve (FFR), hyperaemic trans-stent gradient (HTG), and wall shear stress (WSS) at implantation and at 6-month follow-up in the drug-eluting sirolimus stent and in its bare metal counterpart implanted in pairs within the same patient., Methods and Results: Twenty patients, accepted for percutaneous coronary intervention of at least two coronary arteries with comparable vessel and stenosis characteristics, received at random one sirolimus-eluting stent and one bare metal stent (BMS). Coronary pressure, FFR, HTG, and WSS were measured just after stent implantation and at 6-month follow-up. At 6-month follow-up, FFR was significantly higher in the sirolimus group compared with the bare metal group (0.91+/-0.05 vs. 0.83+/-0.10, P=0.027) and HTG was significantly lower (1.2+/-1.2 vs. 7.5+/-8.1 mmHg, P<0.001). In-stent WSS at 6 months remained normal in the sirolimus group but was elevated in the bare metal group (1.6+/-0.7 vs 3.9+/-3.1 Pa, respectively, P=0.003)., Conclusion: The physiologic characteristics of the drug-eluting sirolimus stents were superior to those of the equivalent BMS. Six months after implantation, FFR was significantly higher, HTG was significantly lower in arteries treated by a sirolimus stent, and normal WSS was maintained within the drug-eluting stent.