Angiography-Derived FFR versus IVUS to Guide PCI According to Angiographic Lesion Characteristics

Background: While angiography-derived fractional flow reserve (AngioFFR) and intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) yield similar outcomes, with AngioFFR associated with lower PCI rates, the relative clinical effectiveness of AngioFFR versus IVUS-guided PCI according to angiographic lesion characteristics remains unclear. Methods: This post-hoc analysis of the FLAVOUR II trial included patients with ≥50% stenosis randomized to AngioFFR- or IVUS-guided PCI. A composite lesion risk score was derived using a marginal Cox model-based linear predictor incorporating % diameter stenosis, lesion length, true bifurcation, ostial lesion, and heavy calcification. The primary endpoint was target vessel failure (TVF: cardiac death, target vessel myocardial infarction, and target vessel revascularization). Results: Among 1,726 patients, 884 (51.2%) underwent AngioFFR-guided PCI and 842 (48.8%) underwent IVUS-guided PCI. During a median 12-month follow-up, TVF occurred in 2.4% of AngioFFR-treated vessels and 1.9% of IVUS-treated vessels (P=0.50). TVF risk increased progressively with higher composite lesion risk score (adjusted hazard ratio [aHR] 2.76; 95% CI 1.35–5.65). This association was more pronounced in the AngioFFR group (aHR 3.93; 95% CI 1.79–8.63) than in the IVUS group (aHR 1.62; 95% CI 0.42–6.22). Compared with IVUS guidance, AngioFFR-guided vessels with high-risk lesion (score >0.32) had a higher TVF rate (5.1% vs. 1.9%, P =0.010), whereas outcomes were comparable in those with low-risk lesions (1.5% vs 1.9%, P =0.531). AngioFFR guidance was associated with lower target vessel PCI rates in low-risk lesion (60.1% vs. 76.5%, P <0.001), whereas PCI rates were uniformly high and similar between groups in high-risk lesions (96.4% vs 97.4%, P =0.675). Conclusions: Higher composite lesion risk score was associated with increased PCI rate and TVF risk after AngioFFR- or IVUS-guided treatment. AngioFFR guidance was associated with lower PCI rates in low-risk lesions, whereas IVUS guidance may yield more favorable outcomes in high-risk lesions.