Impact of Pullback Pressure Gradient on Clinical Outcomes after Percutaneous Coronary Interventions

Background: Impaired flow following percutaneous coronary intervention (PCI) is a known predictor of adverse outcomes. The pullback pressure gradient (PPG) is a novel physiological metric that differentiates focal from diffuse disease and enables prediction of post-PCI fractional flow reserve (FFR). This post hoc analysis of the PPG Global (NCT04789317) study aimed to evaluate the prognostic performance of a PPG model for predicting post-PCI FFR and to determine whether the predicted physiological outcome is associated with adverse events following PCI. Methods: Prospective and multicenter study including patients with hemodynamically significant coronary artery disease undergoing PCI. A prediction model based on FFR and PPG was used to estimate post-PCI FFR. Based on the predicted values, vessels were classified as having either optimal or suboptimal post-PCI physiology. The primary end point was target vessel failure at 1 year. Target vessel failure was defined as a composite of cardiac death, target-vessel myocardial infarction, and ischemia-driven target vessel revascularization. Results: A total of 855 patients (890 vessels) were analyzed. The mean difference between predicted and measured post-PCI FFR was 0.001 (limits of agreement, -0.10 to 0.10). There was a strong correlation between predicted and measured delta FFR (r=0.92 [95% CI, 0.91-0.93]; P<0.001). Vessels with predicted suboptimal post-PCI physiology had a significantly higher incidence of target vessel failure (adjusted hazard ratio,1.97 [95% CI, 1.24-3.15]; P=0.004). Predicted suboptimal physiology was independently associated with adverse clinical outcomes. Conclusions: PPG-predicted post-PCI physiology was associated with target vessel failure at 1 year. These findings extend the role of coronary physiology beyond diagnostic assessment to include risk stratification and outcome prediction following PCI.