Abstract
Background: The impact of diabetes on the management and outcomes of patients with borderline CT-derived fractional flow reserve (FFR(CT)) remains unclear. Methods: This multicenter study enrolled symptomatic patients with suspected coronary artery disease who underwent Coronary computed tomography angiography (CCTA) between June 2021 and May 2023, yielding FFR(CT) values between 0.70 and 0.80. Revascularization occurring within 90 days after CCTA was documented. The endpoint was major adverse cardiovascular events (MACE), as a composite of all-cause death, nonfatal myocardial infarction, and unplanned revascularization. Outcomes were analyzed using Cox proportional hazards models, while the relationship between FFR(CT) and MACE was examined using restricted cubic spline analysis (RCS). Results: This analysis included 1515 patients with borderline FFR(CT) values, comprising 503 (33.2%) with diabetes. Over a median follow-up of 985 days, 117 MACE occurred. Multivariate analysis showed that revascularization was independently associated with a reduced risk of the endpoint, a protective effect consistent in both non-diabetic (adjusted HR [aHR] 0.53, 95% CI 0.29-0.96; p = 0.036) and diabetic patients (aHR 0.25, 95% CI 0.09-0.71; p = 0.009). RCS revealed a significant non-linear relationship between FFR(CT) and MACE in non-diabetic patients (p = 0.002). Conclusions: In patients with borderline FFR(CT), revascularization was linked to a lower incidence of MACE, and this association was consistent regardless of diabetes status.