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 (Comparison of Angiography-Derived Fractional Flow Reserve- and Intravascular Ultrasound-Guided Intervention Strategy for Clinical Outcomes in Patients with Coronary Artery Disease) 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 end point was target vessel failure (TVF: cardiac death, target vessel myocardial infarction, and target vessel revascularization). RESULTS Among 1726 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 a higher composite lesion risk score (adjusted hazard ratio, 2.76 [95% CI, 1.35-5.65]). This association was more pronounced in the AngioFFR group (adjusted hazard ratio, 3.93 [95% CI, 1.79-8.63]) than in the IVUS group (adjusted hazard ratio, 1.62 [95% CI, 0.42-6.22]). Compared with IVUS guidance, AngioFFR-guided vessels with high-risk lesions (score >0.32) had a higher TVF rate (5.1% versus 1.9%; P=0.010), whereas outcomes were comparable in those with low-risk lesions (1.5% versus 1.9%; P=0.531). AngioFFR guidance was associated with lower target vessel PCI rates in low-risk lesions (60.1% versus 76.5%; P<0.001), whereas PCI rates were uniformly high and similar between groups in high-risk lesions (96.4% versus 97.4%; P=0.675). CONCLUSIONS A higher composite lesion risk score was associated with increased PCI rates 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. REGISTRATION URL: https://www.clinicaltrials.gov; Unique identifier: NCT04397211.