Diagnostic accuracy of angiography-based vessel fractional flow reserve after chronic coronary total occlusion recanalization.

BACKGROUND: Angiography-based vessel fractional flow reserve (vFFR) demonstrated a strong correlation with invasive fractional flow reserve (FFR) in both a pre- and post-percutaneous coronary intervention (PCI) setting. However, the role of vFFR and its correlation with post-PCI FFR in chronic coronary occlusions (CTO) has not been evaluated yet. We sought to investigate the diagnostic performance of post-PCI vFFR with post-PCI FFR as a reference in patients undergoing successful CTO PCI. METHODS: Between March 2016 and April 2020, a total of 80 patients from the FFR-SEARCH (prospective registry) and FFR REACT (randomized controlled trial) studies underwent successful CTO recanalization with post-PCI FFR measurements. RESULTS: A total of 50 patients (median age 66 (interquartile range [IQR]: 56-74) years, 76% were male) were eligible for the analysis. Median post-PCI FFR was 0.89 (IQR: 0.84-0.94), while median post-PCI vFFR was 0.91 (IQR: 0.85-0.94) (p 0.10). Suboptimal physiological results, defined as FFR and vFFR <0.90, were identified in 26 (52%) and in 21 (42%) patients, respectively. A strong correlation (r = 0.82) was found between vFFR and FFR with a mean bias of 0.013 ± 0.051. Receiver-operating characteristics curve analysis revealed an excellent accuracy of vFFR in predicting FFR <0.90 (area under the curve: 0.97; 95% confidence interval: 0.93-1.00). CONCLUSION: Post-PCI vFFR shows a good correlation with post-PCI FFR and a high diagnostic accuracy for post-PCI FFR ≤0.90 in patients undergoing successful PCI of a CTO lesion.

Correlation between 3D-QCA based FFR and quantitative lumen assessment by IVUS for left main coronary artery stenoses.

OBJECTIVES: We aimed to evaluate the feasibility of using three dimensional-quantitative coronary angiography (3D-QCA) based fractional flow reserve (FFR) (vessel fractional flow reserve [vFFR], CAAS8.1, Pie Medical Imaging) and to correlate vFFR values with intravascular ultrasound (IVUS) for the evaluation of intermediate left main coronary artery (LMCA) stenosis. BACKGROUND: 3D-QCA derived FFR indices have been recently developed for less invasive functional lesion assessment. However, LMCA lesions were vastly under-represented in first validation studies. METHODS: This observational single-center cohort study enrolled consecutive patients with stable angina, unstable angina, or non-ST-segment elevation myocardial infarction and nonostial, intermediate grade LMCA stenoses who underwent IVUS evaluation. vFFR was computed based on two angiograms with optimal LMCA stenosis projection and correlated with IVUS-derived minimal lumen area (MLA). RESULTS: A total of 256 patients with intermediate grade LMCA stenosis evaluated with IVUS were screened for eligibility; 147 patients met the clinical inclusion criteria and had a complete IVUS LMCA footage available, of them, 63 patients (63 lesions) underwent 3D-QCA and vFFR analyses. The main reason for screening failure was insufficient quality of the angiogram (51 patients,60.7%). Mean age was 65 ± 11 years, 75% were male. Overall, mean MLA within LMCA was 8.77 ± 3.17 mm2 , while mean vFFR was 0.87 ± 0.09. A correlation was observed between vFFR and LMCA MLA (r = .792, p = .001). The diagnostic accuracy of vFFR ≤0.8 in identifying lesions with MLA < 6.0 mm2 (sensitivity 98%, specificity 71.4%, area under the curve (AUC) 0.95, 95% confidence interval (CI) 0.89-1.00, p = .001) was good. CONCLUSIONS: In patients with good quality angiographic visualization of LMCA and available complete LMCA IVUS footage, 3D-QCA based vFFR assessment of LMCA disease correlates well to LMCA MLA as assessed by IVUS.

Wall shear stress estimated by 3D-QCA can predict cardiovascular events in lesions with borderline negative fractional flow reserve.

BACKGROUND AND AIMS: There is some evidence of the implications of wall shear stress (WSS) derived from three-dimensional quantitative coronary angiography (3D-QCA) models in predicting adverse cardiovascular events. This study investigates the efficacy of 3D-QCA-derived WSS in detecting lesions with a borderline negative fractional flow reserve (FFR: 0.81-0.85) that progressed and caused events. METHODS: In this retrospective cohort study, we identified 548 patients who had at least one lesion with an FFR 0.81-0.85 and complete follow-up data; 293 lesions (286 patients) with suitable angiographic characteristics were reconstructed using a dedicated 3D-QCA software and included in the analysis. In the reconstructed models blood flow simulation was performed and the value of 3D-QCA variables and WSS distribution in predicting events was examined. The primary endpoint of the study was the composite of cardiac death, target lesion related myocardial infarction or clinically indicated target lesion revascularization. RESULTS: During a median follow-up of 49.4 months, 37 events were reported. Culprit lesions had a greater area stenosis [(AS), 66.1% (59.5-72.3) vs 54.8% (46.5-63.2), p<0.001], smaller minimum lumen area [(MLA), 1.66 mm2 (1.45-2.30) vs 2.10 mm2 (1.69-2.70), p=0.011] and higher maximum WSS [9.0 Pa (5.10-12.46) vs 5.0 Pa (3.37-7.54), p < 0.001] than those that remained quiescent. In multivariable analysis, AS [hazard ratio (HR): 1.06, 95% confidence interval (CI): 1.03-1.10, p=0.001] and maximum WSS (HR: 1.08, 95% CI: 1.02-1.14, p=0.012) were the only independent predictors of the primary endpoint. Lesions with an increased AS (≥58.6%) that were exposed to high WSS (≥7.69Pa) were more likely to progress and cause events (27.8%) than those with a low AS exposed to high WSS (7.4%) or those exposed to low WSS that had increased (12.8%) or low AS (2.7%, p<0.001). CONCLUSIONS: This study for the first time highlights the potential value of 3D-QCA-derived WSS in detecting, among lesions with a borderline negative FFR, those that cause cardiovascular events.