Routine Fractional Flow Reserve Measurement After Percutaneous Coronary Intervention The FFR-SEARCH Study

BACKGROUND: Fractional flow reserve (FFR) is the current gold standard to determine hemodynamic severity of angiographically intermediate coronary lesions. Much less is known about the prognostic effects of FIR measured directly after percutaneous coronary intervention (PCI). The aims of this study were to evaluate post-PCI FFR values, identify predictors for a low post-PCI FFR, and to investigate whether a relationship between postprocedural FFR and outcome during 30-day follow-up exists. METHODS AND RESULTS: The FFR-SEARCH (Fractional Flow Reserve-Stent Evaluated at Rotterdam Cardiology Hospital) is a prospective registry in which FFR measurements were performed after PCI in 1000 consecutive patients. All FFR measurements were performed under maximum hyperemia with intravenous adenosine with the Navvus RXi system (ACIST Medical Systems, Eden Prairie, MN). The clinical end point was defined as a composite of death, target vessel revascularization, or nonfatal myocardial infarction at 30-day follow-up. Measurement of post-PCI FFR was successful in 959 patients (96%), and a total of 1165 lesions were assessed. There were no complications related to the microcatheter. A total of 322 ST-segment-elevation myocardial infarction patients with 371 measured lesions were excluded leaving 637 patients with 794 measured lesions for the final analysis. Overall post-PCI FFR was 0.90 +/- 0.07. In 396 lesions (50%), post-PCI FFR was >0.90. A total of 357 patients (56%) had >= 1 lesion(s) with a post-PCI FFR <= 0.90, and 73 patients (11%) had >= 1 lesion(s) with a post-PCI FFR <= 0.80 with post-PCI FFR <= 0.80 in 78 lesions (9.8%). Complex lesion characteristics, use of multiple stents and smaller reference vessel diameter was associated with post-PCI FFR <= 0.90. During follow-up, 11 patients (1.8%) reached the clinical end point. There was no significant relationship between post-PCI FFR and the clinical end point at 30-day follow-up (P=0.636). CONCLUSIONS: Routine measurement of post-PCI FFR using a monorail microcatheter is safe and feasible. Several lesion and patient characteristics were associated with a low post-PCI FFR. Post-PCI FFR did not correlate with clinical events at 30 days.