Impact of coronary CT image quality on the accuracy of the FFRCT Planner.

OBJECTIVE: To assess the accuracy of a virtual stenting tool based on coronary CT angiography (CCTA) and fractional flow reserve (FFR) derived from CCTA (FFRCT Planner) across different levels of image quality. MATERIALS AND METHODS: Prospective, multicenter, single-arm study of patients with chronic coronary syndromes and lesions with FFR ≤ 0.80. All patients underwent CCTA performed with recent-generation scanners. CCTA image quality was adjudicated using the four-point Likert scale at a per-vessel level by an independent committee blinded to the FFRCT Planner. Patient- and technical-related factors that could affect the FFRCT Planner accuracy were evaluated. The FFRCT Planner was applied mirroring percutaneous coronary intervention (PCI) to determine the agreement with invasively measured post-PCI FFR. RESULTS: Overall, 120 patients (123 vessels) were included. Invasive post-PCI FFR was 0.88 ± 0.06 and Planner FFRCT was 0.86 ± 0.06 (mean difference 0.02 FFR units, the lower limit of agreement (LLA) - 0.12, upper limit of agreement (ULA) 0.15). CCTA image quality was assessed as excellent (Likert score 4) in 48.3%, good (Likert score 3) in 45%, and sufficient (Likert score 2) in 6.7% of patients. The FFRCT Planner was accurate across different levels of image quality with a mean difference between FFRCT Planner and invasive post-PCI FFR of 0.02 ± 0.07 in Likert score 4, 0.02 ± 0.07 in Likert score 3 and 0.03 ± 0.08 in Likert score 2, p = 0.695. Nitrate dose ≥ 0.8mg was the only independent factor associated with the accuracy of the FFRCT Planner (95%CI - 0.06 to - 0.001, p = 0.040). CONCLUSION: The FFRCT Planner was accurate in predicting post-PCI FFR independent of CCTA image quality. CLINICAL RELEVANCE STATEMENT: Being accurate in predicting post-PCI FFR across a wide spectrum of CT image quality, the FFRCT Planner could potentially enhance and guide the invasive treatment. Adequate vasodilation during CT acquisition is relevant to improve the accuracy of the FFRCT Planner. KEY POINTS: • The fractional flow reserve derived from coronary CT angiography (FFRCT) Planner is a novel tool able to accurately predict fractional flow reserve after percutaneous coronary intervention. • The accuracy of the FFRCT Planner was confirmed across a wide spectrum of CT image quality. Nitrates dose at CT acquisition was the only independent predictor of its accuracy. • The FFRCT Planner could potentially enhance and guide the invasive treatment.

Relationship between coronary volume, myocardial mass, and post-PCI fractional flow reserve.

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.

Ambulatory pulmonary vein isolation workflow using the Perclose ProglideTM suture-mediated vascular closure device: the PRO-PVI study.

AIMS: The leading reason for delayed discharge after pulmonary vein isolation (PVI) is vascular complications. This study aimed to evaluate feasibility, safety, and efficacy of the Perclose Proglide™ suture-mediated vascular closure in ambulatory PVI, report complications, patient satisfaction, and cost of this approach. METHODS AND RESULTS: Patients scheduled for PVI were enrolled prospectively in an observational design. Feasibility was assessed as % discharged the day of procedure. Efficacy was analysed as acute access site closure rate, time to reach haemostasis, time to ambulate, and time to discharge. Safety analysis consisted of vascular complications at 30 days. Cost analysis was reported using direct and indirect cost analysis. A 1:1 propensity matched control cohort was used for comparing time to discharge to usual workflow. Of 50 enrolled patients, 96% were discharged on the same day. 100% of devices were successfully deployed. Immediate (<1 min) haemostasis was reached in 30 patients (62.5%). Mean time to discharge was 5:48 ± 1:03 h (vs. 10:16 ± 1:21 h in the matched cohort, P < 0.0001). Patients reported high level of satisfaction with the post-operative time. No major vascular complication occurred. Cost analysis showed a neutral impact compared to the standard of care. CONCLUSION: The use of the closure device for femoral venous access after PVI led to safe discharge of patients within 6 h from the intervention in 96% of the population. This approach could minimize the overcrowding of healthcare facilities. The gain in post-operative recovery time improved patients' satisfaction and balanced the economic cost of the device.

Development, validation, and reproducibility of the pullback pressure gradient (PPG) derived from manual fractional flow reserve pullbacks.

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.

Influence of fractional flow reserve on grafts patency: Systematic review and patient-level meta-analysis.

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.

Hyperemic hemodynamic characteristics of serial coronary lesions assessed by pullback pressure gradients.

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.

Simplified Assessment of the Index of Microvascular Resistance.

BACKGROUND: To validate a simplified invasive method for the calculation of the index of microvascular resistance (IMR). METHODS: This is a prospective, single-center study of patients with chronic coronary syndromes presenting with nonobstructive coronary artery disease. IMR was obtained using both intravenous (IV) adenosine and intracoronary (IC) papaverine. Each IMR measurement was obtained in duplicate. The primary objective was the agreement between IMR acquired using adenosine and papaverine. Secondary objectives include reproducibility of IMR and time required for the IMR measurement. RESULTS: One hundred and sixteen IMR measurements were performed in 29 patients. The mean age was 68.8 ± 7.24 years, and 27.6% was diabetics. IMR values were similar between papaverine and adenosine (17.7 ± 7.26 and 20.1 ± 8.6, p=0.25; Passing-Bablok coefficient A 0.58, 95% CI -2.42 to 3.53; coefficient B 0.90, 95% CI -0.74 to 1.07). The reproducibility of IMR was excellent with both adenosine and papaverine (ICC 0.78, 95% CI 0.63 to 0.88 and ICC 0.93, 95% CI 0.87 to 0.97). The time needed for microvascular assessment was significantly shortened by the use of IC papaverine (3.23 (2.84, 3.78) mins vs. 5.48 (4.94, 7.09) mins, p < 0.0001). CONCLUSION: IMR can be reliably measured using IC papaverine with similar results compared to intravenous infusion of adenosine with increased reproducibility and reduced procedural time. This approach simplifies the invasive assessment of the coronary microcirculation in the catheterization laboratory.

Incremental Predictive Value of Coronary Calcium Score in Risk Stratification of Coronary Revascularization in Patients With Normal or Mild Ischemia Using Nuclear Myocardial Perfusion Single Photon Emission Computed Tomography.

BACKGROUND: The incremental predictive value of the coronary artery calcium score (CACS) for risk stratification of coronary revascularization in patients with normal or mildly abnormal nuclear myocardial perfusion single photon emission computed tomography (MPS) scores is unknown.Methods and Results:We analyzed 528 patients in whom CACS was calculated and who underwent stress MPS within 3 months. Patients with known coronary artery disease, prior coronary revascularization, and those undergoing hemodialysis were excluded. Patients were followed-up with coronary revascularization based on the evidence of physiological ischemia defined by fractional flow reserve or severe coronary stenosis (≥90%). CACS was significantly associated with the summed stress score (SSS) from MPS assessment. Multivariate logistic regression analysis showed that high CACS (≥300; odds ratio [OR] 5.44, 95% confidence interval [CI] 2.28-13.0) and SSS (OR 1.29, 95% CI 1.18-1.40) were significant (P<0.001) predictors of future coronary revascularization. The log-rank test showed that high CACS stratified coronary revascularization in normal SSS (0-3; P<0.001) or mildly abnormal SSS (4-8; P=0.028) groups, whereas high CACS did not significantly stratify coronary revascularization in moderate to severe SSS (≥9; P=0.757). CONCLUSIONS: Risk stratification using CACS with a cut-off value 300 may have incremental predictive value for revascularization in patients with normal or mildly abnormal MPS.

The Prognostic Value of Left Atrial Reservoir Functional Indices Measured by Three-Dimensional Speckle-Tracking Echocardiography for Major Cardiovascular Events.

BACKGROUND: Left atrial (LA) volume and left ventricular longitudinal strain (LVLS) have significant prognostic values for major cardiovascular events (MACEs). Prognostic values of LA reservoir functional indices measured by 3-dimensional (3D) speckle-tracking echocardiography (STE) were evaluated.Methods and Results:A total of 264 patients, who underwent 2-dimensional (2D) echocardiography and 3DSTE for various underlying heart diseases, were followed up to record MACE. After a mean follow up of 547±435 days, 30 patients developed MACE: 7 cardiac deaths, 6 strokes, 1 non-fatal myocardial infarction, and 22 admissions for heart failure (5 of these had cardiac death after discharge, whereas 1 sustained stroke after discharge). Receiver operating characteristic curve analysis was performed to determine the optimal cut-off levels of 4 LA functional indices: LA emptying fraction (LAEmpF), LA longitudinal strain (LALS), LA circumferential strain (LACS), and LA area change ratio (LAAC), using 3DSTE. Among these factors, 2DLVLS, 3DLAEmpF, and 3DLALS demonstrated a higher hazard ratio (>5.0) than other variables. The 3DLAEmpF and 3DLALS had a higher average treatment effect (ATE) and ATE on the treated (ATT), respectively, than the other indices after propensity score matching. Addition of 3DLAEmpF to the base model using clinical variables and LV ejection fraction or 2DLVLS demonstrated higher prognostic power. CONCLUSIONS: LAEmpF calculated using 3DSTE possessed additive prognostic values for the prediction of MACE.

Vessel Fractional Flow Reserve and Graft Vasculopathy in Heart Transplant Recipients.

BACKGROUND: Cardiac allograft vasculopathy (CAV) remains the Achilles' heel of long-term survival after heart transplantation (HTx). The severity and extent of CAV is graded with conventional coronary angiography (COR) which has several limitations. Recently, vessel fractional flow reserve (vFFR) derived from COR has emerged as a diagnostic computational tool to quantify the functional severity of coronary artery disease. PURPOSE: The present study assessed the usefulness of vFFR to detect CAV in HTx recipients. METHODS: In HTx patients referred for annual check-up, undergoing surveillance COR, the extent of CAV was graded according to the criteria proposed by the international society of heart and lung transplantation (ISHLT). In addition, three-dimensional coronary geometries were constructed from COR to calculate pressure losses using vFFR. RESULTS: In 65 HTx patients with a mean age of 53.7 ± 10.1 years, 8.5 years (IQR 1.90, 15.2) years after HTx, a total number of 173 vessels (59 LAD, 61 LCX, and 53 RCA) were analyzed. The mean vFFR was 0.84 ± 0.15 and median was 0.88 (IQR 0.79, 0.94). A vFFR ≤ 0.80 was present in 24 patients (48 vessels). HTx patients with a history of ischemic cardiomyopathy (ICMP) had numerically lower vFFR as compared to those with non-ICMP (0.70 ± 0.22 vs. 0.79 ± 0.13, p = 0.06). The use of vFFR reclassified 31.9% of patients compared to the anatomical ISHLT criteria. Despite a CAV score of 0, a pathological vFFR ≤ 0.80 was detected in 8 patients (34.8%). CONCLUSION: The impairment in epicardial conductance assessed by vFFR in a subgroup of patients without CAV according to standard ISHLT criteria suggests the presence of a diffuse vasculopathy undetectable by conventional angiography. Therefore, we speculate that vFFR may be useful in risk stratification after HTx.

Prognostic Value of Left Atrial Size and Functional Indices Measured by 3-Dimensional Speckle-Tracking Analysis.

BACKGROUND: The prognostic value of indices for left atrial volumes (LAV) and reservoir function measured by 3D speckle-tracking analysis (3DSTA) has not been determined. Methods and Results: LA maximal and minimal volume indices (LAVImax, LAVImin), and LA emptying fraction (LAEmpF) were measured via 2D echocardiography (2DE) and 3DSTA in 514 patients (62% male, mean age: 66±15 years) with various cardiovascular diseases. Two cutoff values using normal±2SD (cutoff criterion 1) and receiver-operating characteristic analysis (cutoff criterion 2) were evaluated. During a mean follow-up of 720±383 days, MACE (cardiac death, nonfatal myocardial infarction, stroke and admission for heart failure) occurred in 98 patients. Kaplan-Meier survival analysis showed both cutoff criteria measured by 2DE and 3DSTA had significant predictive power for MACE (P<0.001). For cutoff criterion 1, 3DSTA measurements yielded higher hazard ratios than 2DE by Cox proportional hazard model. Cutoff criterion 2 using 3DSTA had higher average treatment effect values than 2DE by matching propensity scores on the outcome. Further, a regression model that included clinical variables, left ventricular ejection fraction and cutoff criterion 2 using 3DSTA-derived LAEmpF had significantly higher prognostic power than 2DE. CONCLUSIONS: LA indices measured by 3DSTA had greater prognostic power for future MACE than 2DE. In particular, 3DSTA-derived LAEmpF has the potential to be a valuable prognostic tool in clinical settings.

Development of a model predicting cardiac events in heart failure patients with decreased renal function: a retrospective study.

BACKGROUND: Inappropriate and multiple medications affect the prognosis of patients with acute decompensated heart failure (ADHF). However, in ADHF patients with decreased renal function, there have been no reports on prognostic factors, including medication data, or models for predicting cardiac events. AIM: To develop a model including medication data to predict cardiac events in ADHF patients with decreased renal function. METHOD: This retrospective cohort study included 443 first-time admitted ADHF patients with decreased renal function (estimated glomerular filtration rate < 60 mL/min/1.73 m2 at discharge) in the Showa University Fujigaoka Hospital. The primary outcome was cardiac events within one year after discharge, defined as the composite of HF readmission, HF mortality, and cardiovascular mortality. The model for predicting cardiac events was developed using predictive factors extracted by multivariable analysis. The cardiac events curves were visualized using the Kaplan-Meier method and estimated using a log-rank test. RESULTS: The incidence of cardiac events within one year after discharge was 20.1%. By multivariable analysis, we observed that atrial fibrillation, weight loss < 5%, brain natriuretic peptide ≥ 200 pg/mL, polypharmacy, and beta-blockers use below target dosage were significantly associated with an increased risk of cardiac events. The developed model, the cardiac events rate in the high-risk group was significantly higher than in the low-risk group (41.0 vs. 9.2%, p < 0.001). CONCLUSION: The developed model for predicting cardiac events will be useful in decision-making to support appropriate early management of ADHF patients with decreased renal function.

Cardiac Structure and Cardiorespiratory Fitness in Young Male Japanese Rugby Athletes.

Limited data are available on athlete's heart for rugby athletes. This study aimed to investigate cardiac structure and its relationship with cardiorespiratory fitness in young Japanese rugby athletes. A prospective cross-sectional study using echocardiography and cardiopulmonary exercise testing (CPET) was conducted on 114 male collegiate rugby players. There was a higher prevalence of increased left ventricular (LV), atrial, and aortic dimensions in the young athletes than that in previously published reports, whereas the wall thickness was within the normal range. Anthropometry and CPET analyses indicated that the forwards and backs presented muscular and endurance phenotypes, respectively. Indexed LV and aortic dimensions were significantly larger in the backs than in the forwards, and the dimensions significantly correlated with oxygen uptake measured by CPET. On the four-tiered classification for LV hypertrophy, abnormal LV geometry was found in 16% of the athletes. Notably, the resting systolic blood pressure was significantly higher in athletes with concentric abnormal geometry than in the other geometry groups, regardless of their field positions. Japanese young athletes may exhibit unique phenotypes of cardiac remodeling in association with their fitness characteristics. The four-tiered LV geometry classification potentially offers information regarding the subclinical cardiovascular risks of young athletes.

Diagnostic performance of exercise stress tests for detection of epicardial and microvascular coronary artery disease: the UZ Clear study.

BACKGROUND: Cardiac stress tests remain the cornerstone for evaluating patients suspected of having obstructive coronary artery disease (CAD). Coronary microvascular dysfunction (CMD) can lead to abnormal non-invasive tests. AIMS: We sought to assess the diagnostic performance of exercise stress tests with indexes of epicardial and microvascular resistance as reference. METHODS: This was a prospective, single-arm, multicentre study of patients with an intermediate pretest probability of CAD and positive exercise stress tests who were referred for invasive angiography. Patients underwent an invasive diagnostic procedure (IDP) with measurement of fractional flow reserve (FFR) and index of microvascular resistance (IMR) in at least one coronary vessel. Obstructive CAD was defined as diameter stenosis (DS) >50% by quantitative coronary angiography (QCA). The objective was to determine the false discovery rate (FDR) of cardiac exercise stress tests with both FFR and IMR as references. RESULTS: One hundred and seven patients (137 vessels) were studied. The mean age was 62.1±8.7, and 27.1% were female. The mean diameter stenosis was 37.2±27.5%, FFR was 0.84±0.10, coronary flow reserve was 2.74±2.07, and IMR 20.3±11.9. Obstructive CAD was present in 39.3%, whereas CMD was detected in 20.6%. The FDR was 60.7% and 62.6% with QCA and FFR as references (p-value=0.803). The combination of FFR and IMR as clinical reference reduced the FDR by 25% compared to QCA (45.8% vs 60.7%; p-value=0.006). CONCLUSIONS: In patients with evidence of ischaemia, an invasive functional assessment accounting for the epicardial and microvascular compartments led to an improvement in the diagnostic performance of exercise tests, driven by a significant FDR reduction.

Prevalence of Coronary Microvascular Disease and Coronary Vasospasm in Patients With Nonobstructive Coronary Artery Disease: Systematic Review and Meta-Analysis.

Background A relevant proportion of patients with suspected coronary artery disease undergo invasive coronary angiography showing normal or nonobstructive coronary arteries. However, the prevalence of coronary microvascular disease (CMD) and coronary spasm in patients with nonobstructive coronary artery disease remains to be determined. The objective of this study was to determine the prevalence of coronary CMD and coronary vasospastic angina in patients with no obstructive coronary artery disease. Methods and Results A systematic review and meta-analysis of studies assessing the prevalence of CMD and vasospastic angina in patients with no obstructive coronary artery disease was performed. Random-effects models were used to determine the prevalence of these 2 disease entities. Fifty-six studies comprising 14 427 patients were included. The pooled prevalence of CMD was 0.41 (95% CI, 0.36-0.47), epicardial vasospasm 0.40 (95% CI, 0.34-0.46) and microvascular spasm 24% (95% CI, 0.21-0.28). The prevalence of combined CMD and vasospastic angina was 0.23 (95% CI, 0.17-0.31). Female patients had a higher risk of presenting with CMD compared with male patients (risk ratio, 1.45 [95% CI, 1.11-1.90]). CMD prevalence was similar when assessed using noninvasive or invasive diagnostic methods. Conclusions In patients with no obstructive coronary artery disease, approximately half of the cases were reported to have CMD and/or coronary spasm. CMD was more prevalent among female patients. Greater awareness among physicians of ischemia with no obstructive coronary arteries is urgently needed for accurate diagnosis and patient-tailored management.

Risk of myocardial infarction based on endothelial shear stress analysis using coronary angiography.

BACKGROUND AND AIMS: Wall shear stress (WSS) has been associated with atherogenesis and plaque progression. The present study assessed the value of WSS analysis derived from conventional coronary angiography to detect lesions culprit for future myocardial infarction (MI). METHODS AND RESULTS: Three-dimensional quantitative coronary angiography (3DQCA), was used to calculate WSS and pressure drop in 80 patients. WSS descriptors were compared between 80 lesions culprit of future MI and 108 non-culprit lesions (controls). Endothelium-blood flow interaction was assessed by computational fluid dynamics (10.8 ± 1.41 min per vessel). Median time between baseline angiography and MI was 25.9 (21.9-29.8) months. Mean patient age was 70.3 ± 12.7. Clinical presentation was STEMI in 35% and NSTEMI in 65%. Culprit lesions showed higher percent area stenosis (%AS), translesional vFFR difference (ΔvFFR), time-averaged WSS (TAWSS) and topological shear variation index (TSVI) compared to non-culprit lesions (p < 0.05 for all). TSVI was superior to TAWSS in predicting MI (AUC-TSVI = 0.77, 95%CI 0.71-0.84 vs. AUC-TAWSS = 0.61, 95%CI 0.53-0.69, p < 0.001). The addition of TSVI increased predictive and reclassification abilities compared to a model based on %AS and ΔvFFR (NRI = 1.04, p < 0.001, IDI = 0.22, p < 0.001). CONCLUSIONS: A 3DQCA-based WSS analysis was feasible and can identify lesions culprit for future MI. The combination of area stenoses, pressure gradients and WSS predicted the occurrence of MI. TSVI, a novel WSS descriptor, showed strong predictive capacity to detect lesions prone to cause MI.

Procedural Outcomes After Percutaneous Coronary Interventions in Focal and Diffuse Coronary Artery Disease.

Background Coronary artery disease (CAD) patterns play an essential role in the decision-making process about revascularization. The pullback pressure gradient (PPG) quantifies CAD patterns as either focal or diffuse based on fractional flow reserve (FFR) pullbacks. The objective of this study was to evaluate the impact of CAD patterns on acute percutaneous coronary intervention (PCI) results considered surrogates of clinical outcomes. Methods and Results This was a prospective, multicenter study of patients with hemodynamically significant CAD undergoing PCI. Motorized FFR pullbacks and optical coherence tomography (OCT) were performed before and after PCI. Post-PCI FFR >0.90 was considered an optimal result. Focal disease was defined as PPG >0.73 (highest PPG tertile). Overall, 113 patients (116 vessels) were included. Patients with focal disease were younger than those with diffuse CAD (61.4±9.9 versus 65.1±8.7 years, P=0.042). PCI in vessels with high PPG (focal CAD) resulted in higher post-PCI FFR (0.91±0.07 in the focal group versus 0.86±0.05 in the diffuse group, P<0.001) and larger minimal stent area (6.3±2.3 mm2 in focal versus 5.3±1.8 mm2 in diffuse CAD, P=0.015) compared withvessels with low PPG (diffuse CAD). The PPG was associated with the change in FFR after PCI (R2=0.51, P<0.001). The PPG significantly improved the capacity to predict optimal PCI results compared with an angiographic assessment of CAD patterns (area under the curvePPG 0.81 [95% CI, 0.73-0.88] versus area under the curveangio 0.51 [95% CI, 0.42-0.60]; P<0.001). Conclusions PCI in vessels with focal disease defined by the PPG resulted in greater improvement in epicardial conductance and larger minimal stent area compared with diffuse disease. PPG, but not angiographically defined CAD patterns, distinguished patients attaining superior procedural outcomes. Registration URL: https://clinicaltrials.gov/ct2/show/NCT03782688.

Clinical Validation of a Virtual Planner for Coronary Interventions Based on Coronary CT Angiography.

BACKGROUND: Low fractional flow reserve (FFR) values after percutaneous coronary intervention (PCI) carry a worse prognosis than high post-PCI FFR values. Therefore, the ability to predict post-PCI FFR might play an important role in procedural planning. Post-PCI FFR values can now be computed from pre-PCI coronary computed tomography angiography (CTA) using the fractional flow reserve derived from coronary computed tomography angiography revascularization planner (FFRCT Planner). OBJECTIVES: The aim of this study was to validate the accuracy of the FFRCT Planner. METHODS: In this multicenter, investigator-initiated, prospective study, patients with chronic coronary syndromes and significant lesions based on invasive FFR ≤0.80 were recruited. The FFRCT Planner was applied to the fractional flow reserve derived from coronary computed tomography angiography (FFRCT) model, simulating PCI. The primary objective was the agreement between the predicted post-PCI FFR by the FFRCT Planner and measured post-PCI FFR. Accuracy of the FFRCT Planner's luminal dimensions was assessed by using post-PCI optical coherence tomography as the reference. RESULTS: Overall, 259 patients were screened, with 120 patients (123 vessels) included in the final analysis. The mean patient age was 64 ± 9 years, and 24% had diabetes. Measured FFR post-PCI was 0.88 ± 0.06, and the FFRCT Planner FFR was 0.86 ± 0.06 (mean difference: 0.02 ± 0.07 FFR unit; limits of agreement: -0.12 to 0.15). Optical coherence tomography minimal stent area was 5.60 ± 2.01 mm2, and FFRCT Planner minimal stent area was 5.0 ± 2.2 mm2 (mean difference: 0.66 ± 1.21 mm2; limits of agreement: -1.7 to 3.0). The accuracy and precision of the FFRCT Planner remained high in cases with focal and diffuse disease and with low and high calcium burden. CONCLUSIONS: The FFRCT-based technology was accurate and precise for predicting FFR after PCI. (Precise Percutaneous Coronary Intervention Plan Study [P3]; NCT03782688).

Validation of Coronary Angiography-Derived Vessel Fractional Flow Reserve in Heart Transplant Patients with Suspected Graft Vasculopathy.

Cardiac transplant-related vasculopathy remains a leading cause of morbidity and mortality in heart transplant (HTx) recipients. Recently, coronary angiography-derived vessel fractional flow reserve (vFFR) has emerged as a new diagnostic computational tool to functionally evaluate the severity of coronary artery disease. Although vFFR estimates have been shown to perform well against invasive FFR in atherosclerotic coronary artery disease, data on the use of vFFR in heart transplant recipients suffering from cardiac transplant-related arteriopathy are lacking. The aim of the presented study was to validate coronary angiography-derived vessel fractional flow reserve to calculate fractional flow reserve in HTx patients with and without cardiac transplant-related vasculopathy. A prospective, single center study of HTx patients referred for annual check-up, undergoing surveillance coronarography was conducted. Invasive FFR was measured using a motorized device at the speed of 1.0 mm/s in all three major coronary arteries. Angiography-derived pullback FFR was derived from the angiogram and compared with invasive FFR pullback curve. Overall, 18,059 FFR values were extracted from the FFR pullback curves from 23 HTx patients. The mean age was 59.3 ± 9.7 years, the mean time after transplantation was 5.24 years [IQR 1.20, 11.25]. A total of 39 vessels from 23 patients (24 LAD, 11 LCX, 4 RCA) were analyzed. Mean distal vFFR was 0.87 ± 0.14 whereas invasive distal FFR was 0.88 ± 0.17. An excellent correlation was found between invasive distal FFR and vFFR (r = 0.92; p < 0.001). The correlation of the pullback tracing was high, with a correlation coefficient between vFFR and invasive FFR pullback values of 0.72 (95% CI 0.71 to 0.73, p < 0.001). The mean difference between vFFR and invasive FFR pullback values was -0.01 with 0.06 of SD (limits of agreements -0.12 to 0.13). In HTx patients, coronary angiography-derived FFR correlates excellently with invasively measured wire-derived FFR. Therefore, angiography derived FFR could be used as a novel diagnostic tool to quantify the functional severity of graft vasculopathy.