The impact of residual vessel fractional flow reserve on clinical outcomes: The FAST residual study

Backgrounds Vessel fractional flow reserve (vFFR) allows angiography-based physiological lesion evaluation and virtual percutaneous coronary intervention (PCI) simulation, estimating post-PCI vFFR (residual vFFR). While residual vFFR has been validated against invasive post-PCI fractional flow reserve (FFR), its clinical significance remains unclear. To assess the impact of residual vFFR on long-term clinical outcomes. Methods FAST Residual is a post hoc analysis of the FFR SEARCH study including 279 patients with (un)stable angina or non-ST-segment elevation myocardial infarction undergoing angiographically successful PCI. Residual vFFR was calculated based on two pre-procedural angiographic views. The primary endpoint was target vessel failure (TVF) at 5 years, a composite of cardiac death, target vessel myocardial infarction (TVMI) and target vessel revascularization (TVR). Results Mean age was 64 ± 11 years, 68.5% were men, 23.7% had diabetes, and 43.7% presented with stable angina. Median residual vFFR was 0.92 [IQR 0.87–0.95] and post-PCI FFR was 0.90 [0.85–0.94] ( r = 0.509, p < 0.001). The optimal cutoff value of residual vFFR to predict 5-year TVF was <0.90. TVF occurred in 24 (23.3%) patients in the residual vFFR <0.90 group, compared with 16 (9.1%) in the residual vFFR ≥0.90 group (adjusted HR 2.66, 95% CI 1.41–5.04; p = 0.003). This difference was driven by higher rates of TVR [16 (15.5%) vs. 12 (6.8%); adjusted HR 2.33, 95% CI 1.10–4.94; p = 0.027]. Conclusions The concept of virtual stenting is a promising tool for predicting clinical outcomes. For the first time, this post hoc analysis showed that patients with residual vFFR <0.90 experienced significantly higher rates of TVF at 5 years.