Prognostic implication of computational angiography-derived fractional flow reserve in patients with non-obstructive coronary artery disease

Abstract Background Non-obstructive coronary artery disease (NOCAD) is proved to have high association with rate of major adverse cardiovascular events (MACE) in recent studies, yet risk stratification of symptomatic Non-Obstructive Coronary Artery Disease (NOCAD) patients remains uncertain. Objectives Our study assessed clinical value of single-vessel, multi-vessel, and three-vessel computational angiography-derived fractional flow reserve (caFFR) measurement in NOCAD patients. Methods We enrolled patients with ≤ 50% stenosis with a caFFR value ≥ 0.8 in all three coronary arteries on coronary angiography. The sum of caFFR values in the three vessels was computed for each patient. Patient stratification was based on median value of the following criteria: single vessel analysis, multi-vessel analysis, 3-vessel (3V) analysis. The primary endpoint of this study was major adverse cardiac events (MACE) at 5 years, defined as a composite of cardiac death, myocardial infarction, and ischemia-driven revascularization. Results A total of 490 patients were included (mean age 64.39 ± 11.16, 55.5% male). The 5-year MACE rates in single-vessel analysis were statistically insignificant between low and high caFFR groups (Left anterior descending artery (P=0.163); Left circumflex artery (P=0.797); Right coronary artery (P=0.127)). In multi-vessel analysis, patients in multiple-vessel low-caFFR group (with 2-3 vessels lower than median value of all coronary arteries) show an increased risk of 5-year MACE than patients in single-vessel low-caFFR group (0-1 vessel) (hazard ratio [HR] 2.648, 95% confidence interval [CI] 1.141 - 6.145, P = 0.023). In 3-vessel analysis, patients in the low 3V-caFFR group demonstrated a greater 5-year MACE risk than the high 3V-caFFR group ([HR] 2.43, 95% 95%[CI] 1.087 - 5.433, P = 0.031). Conclusion In patients with NOCAD, the higher count of vessels exhibiting with low caFFR values and the low 3V-caFFR values have been found to be associated with increased rate of MACE over a 5-year period. We demonstrated that both multiple-vessel and 3V-caFFR measurements serve as valuable prognostic indicators for risk assessment in NOCAD patients.