Predictors of postprocedural fractional flow reserve: Insights from the FFR-SEARCH study

Introduction and objectives: Patients with a low post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR) are at a higher risk for future adverse cardiac events. The objective of the current study was to assess specific patient and procedural predictors of post-PCI FFR. Methods: The FFR-SEARCH study is a prospective single-center registry of 1000 consecutive all-comer patients who underwent FFR measurements after an angiographically successful PCI with a dedicated microcatheter. Mixed effects models were used to search for independent predictors of post-PCI FFR. Results: The mean post-PCI distal coronary pressure divided by the aortic pressure (Pd/Pa) was 0.96 ± 0.04 and the mean post-PCI FFR, 0.91 ± 0.07. After adjusting for the independent predictors of post-PCI FFR, the left anterior descending coronary artery as the measured vessel was the strongest predictor of post-PCI FFR (adjusted β = -0.063; 95%CI, -0.070 to -0.056; P <.0001) followed by the postprocedural minimum lumen diameter (adjusted β = 0.039; 95%CI, 0.015-0.065; P =.002). Additionally, male sex, in-stent restenosis, chronic total coronary occlusions, and pre- and post-dilatation were negatively associated with postprocedural FFR. Conversely, type A lesions, thrombus-containing lesions, postprocedural percent stenosis, and stent diameter were positively associated with postprocedural FFR. The R² for the complete model was 53%. Conclusions: Multiple independent patient and vessel related predictors of postprocedural FFR were identified, including sex, the left anterior descending coronary artery as the measured vessel, and postprocedural minimum lumen diameter.