Impact of Poststenting Fractional Flow Reserve on Long-Term Clinical Outcomes: The FFR-SEARCH Study

Background: Fractional flow reserve (FFR)-guided treatment has been demonstrated to improve percutaneous coronary intervention (PCI) results. However, little is known on the long-term impact of low post-PCI FFR. Methods: This is a large prospective all comers study evaluating the impact of post-PCI FFR on clinical outcomes. All patients undergoing successful PCI were eligible for enrollment. FFR measurements were performed immediately after PCI when the operator considered the angiographic result acceptable and final. No further action was undertaken based on the post-PCI result. Suboptimal post-PCI FFR was defined as FFR<0.90. The primary end point was major adverse cardiac events, a composite of cardiac death, any myocardial infarction, or any revascularization at 2-year follow-up. Secondary end points were target vessel revascularizations and stent thrombosis and the separate components of the primary end point. Results: A total of 1000 patients were enrolled. Post-PCI FFR was successfully measured in 1165 vessels from 959 patients. A poststenting FFR<0.90 was observed in 440 vessels (37.8%). A total of 399 patients had at least 1 vessel with FFR<0.90 post-PCI. At 2-year follow-up, a patient level analysis showed no association between post-PCI FFR and major adverse cardiac event (hazard ratio [HR], 1.08 [95% CI, 0.73-1.60], P=0.707), cardiac death (HR, 1.55 [95% CI, 0.72-3.36], P=0.261), any myocardial infarction (HR, 1.53 [95% CI, 0.78-3.02], P=0.217). A vessel level analysis showed a higher rate of target vessel revascularization (HR, 1.91 [95% CI, 1.06-3.44], P=0.030) and a tendency toward higher rate of stent thrombosis (HR, 2.89 [95% CI, 0.88-9.48], P=0.081) with final post-PCI FFR<0.90. Conclusions: Suboptimal post-PCI FFR has only a moderate impact on major adverse cardiac event but coronary arteries with a post-PCI FFR<0.90 have a higher rate of target vessel revascularization.