Percutaneous Coronary Intervention in Native Coronary Arteries Versus Bypass Grafts in Patients With Prior Coronary Artery Bypass Graft Surgery: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program

The aim of this study was to examine the frequency, associations, and outcomes of native coronary artery versus bypass graft percutaneous coronary intervention (PCI) in patients with prior coronary artery bypass grafting (CABG) in the Veterans Affairs (VA) integrated health care system. Patients with prior CABG surgery often undergo PCI, but the association between PCI target vessel and short- and long-term outcomes has received limited study. A national cohort of 11,118 veterans with prior CABG who underwent PCI between October 2005 and September 2013 at 67 VA hospitals was examined, and the outcomes of patients who underwent native coronary versus bypass graft PCI were compared. Logistic regression with generalized estimating equations was used to adjust for correlation between patients within hospitals. Cox regressions were modeled for each outcome to determine the variables with significant hazard ratios (HRs). During the study period, patients with prior CABG represented 18.5% of all patients undergoing PCI (11,118 of 60,171). The PCI target vessel was a native coronary artery in 73.4% and a bypass graft in 26.6%: 25.0% in a saphenous vein graft and 1.5% in an arterial graft. Compared with patients undergoing native coronary artery PCI, those undergoing bypass graft PCI had higher risk characteristics and more procedure-related complications. During a median follow-up period of 3.11 years, bypass graft PCI was associated with significantly higher mortality (adjusted HR: 1.30; 95% confidence interval: 1.18 to 1.42), myocardial infarction (adjusted HR: 1.61; 95% confidence interval: 1.43 to 1.82), and repeat revascularization (adjusted HR: 1.60; 95% confidence interval: 1.50 to 1.71). In a national cohort of veterans, almost three-quarters of PCIs performed in patients with prior CABG involved native coronary artery lesions. Compared with native coronary PCI, bypass graft PCI was significantly associated with higher incidence of short- and long-term major adverse events, including more than double the rate of in-hospital mortality.