Lower Repeat Revascularization Rates Among Patients With Prior Coronary Artery Bypass Graft Surgery are Due to Lack of Adequate Target Vessels

Background. Studies comparing percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) surgery in patients with multivessel coronary artery disease (CAD) have shown lower repeat revascularization rates in patients who undergo CABG. The reason remains unclear. Methods. We identified patients with multivessel CAD who received CABG or PCI enrolled in the Duke Databank for Cardiovascular Disease (2003 to 2012). We compared the incidence of major adverse cardiovascular and cerebrovascular events (MACCE) between the two groups. Clinically performed follow-up angiograms for CABG patients were reviewed to determine adequacy of intervenable targets. Results. A total of 1555 patients were included: 861 underwent PCI and 694 underwent CABG. Patients with index PCI were more often female, African-American, presented with ST-elevation myocardial infarction (MI), and had previous MI; they were less often diabetic and had less heart failure or proximal left anterior descending disease. The adjusted hazard ratio of MACCE for CABG vs PCI was 0.68 (95% confidence interval, 0.58-0.80; P<.001). The adjusted odds ratio for repeat revascularization for CABG vs PCI was 0.45 (95% confidence interval, 0.28-0.72; P<.001). Fifty-seven patients with index CABG were found to have >= 1 occluded graft on subsequent angiography without repeat revascularization; 48 patients (6.9%) had inadequate targets for intervention. Conclusion. Among patients with multivessel CAD, repeat revascularization rates are lower among CABG patients compared with PCI patients. However, a high proportion of CABG patients with occluded grafts on repeat angiography lack targets for repeat revascularization. This may partially explain the disparity in repeat revascularization rates and suggests that future comparison studies should additionally assess angiographic outcomes.