Impact of Post Percutaneous Coronary Intervention Fractional Flow Reserve on 5‐Year Clinical Outcomes (The FFR SEARCH Study)

BACKGROUND: Fractional flow reserve (FFR) following percutaneous coronary intervention (PCI) can be used to evaluate procedural success and to guide stent optimization. Several studies have demonstrated that lower FFR after stent implantation is associated with increased adverse event rates up to 2 years. However, the impact of post-PCI FFR on very long-term clinical outcome remains unknown. METHODS: The FFR SEARCH study is a single-center, prospective, observational study including consecutive patients undergoing PCI with stent implantation from 2016 to 2017. FFR measurement was performed after angiographically successful PCI using a dedicated microcatheter. The primary endpoint was target vessel failure (TVF) at 5 years, a composite of cardiovascular death, target vessel myocardial infarction and target vessel revascularization. The optimal post-PCI FFR cutoff value to predict 5-year TVF was determined based on the maximum log-rank statistic. RESULTS: Post-PCI FFR measurements were successfully performed in 959 patients. Mean age was 64.0 ± 11.9 years, 72.5% of the patients were male and 33.6% presented with ST-segment elevation myocardial infarction. The left anterior descending artery was the target vessel in 53.5%. The optimal post-PCI FFR cutoff value was ≤ 0.90. TVF occurred in 18.4% of patients with a post-PCI FFR ≤ 0.90 versus 11.6% in patients with a post-PCI FFR > 0.90 (adjusted HR 1.65 (95% CI 1.11-2.48, p = 0.014)). CONCLUSIONS: This large prospective observational study demonstrates that post-PCI FFR ≤ 0.90 is associated with a higher TVF rate at 5 years.