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