Impact of Coronary Artery Disease Patterns Assessed with Pullback Pressure Gradient on Clinical Outcomes: Meta-analysis

BACKGROUND AND AIMS Diffuse coronary artery disease (CAD) impacts patients' outcomes; however, its definition is not objectively established and varies across studies. Pullback pressure gradient (PPG) is a novel physiological index for quantitatively evaluating the pattern of CAD; nevertheless, its clinical utility has not been fully elucidated. This study aims to comprehensively assess the PPG prognostic impact on clinical and physiological outcomes. METHODS The EMBASE, Medline, and PubMed databases were searched, following the PRISMA guidelines. Studies reporting pre-percutaneous coronary intervention (PCI) PPG measurements and post-PCI physiological indices or clinical outcomes were included. Data on clinical events were extracted at the longest reported follow-up. The primary endpoint for this meta-analysis was the composite of clinical events (major adverse cardiovascular events [MACE] or target vessel failure [TVF]). RESULTS Thirteen studies were included in the analyses. In five studies, pullbacks were performed using an invasive approach, whilst eight used an angio-based method. The correlation between PPG and post-PCI fractional flow reserve (FFR) values was moderate (r =0.44, 95%CI:0.34-0.52, p < 0.001). Compared to focal lesions, diffuse lesions had significantly lower post-PCI FFRs (mean difference = -0.05, -0.07 to -0.04, p < 0.001) and significantly more frequent (RR = 1.93, 95%CI:1.76-2.11, p < 0.001) suboptimal post-PCI physiological results (defined as low post-PCI FFR). Diffuse lesions were significantly associated with the composite of clinical events (RR = 1.71, 1.34-2.20, p < 0.001), MACE, TVF, myocardial infarction, and target vessel revascularization. CONCLUSIONS The pattern of coronary artery disease, as defined using PPG, significantly impacts physiological results post-PCI and the risk of cardiovascular events.