Incidence, predictors and outcomes of incomplete revascularization after percutaneous coronary intervention and coronary artery bypass grafting: A subgroup analysis of 3-year SYNTAX data

Objective: To assess whether incomplete revascularization by percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) has an effect on long-term outcomes. Methods: During a heart team discussion to evaluate whether patients were eligible for randomization in the SYNTAX trial, both the cardiologist and surgeon agreed on which vessels needed revascularization. This statement was compared with the actual revascularization after treatment. Incomplete revascularization was defined as when a preoperatively identified vessel with a lesion was not revascularized. Outcomes were major adverse cardiac or cerebrovascular events (MACCE), the composite safety endpoint of death/ stroke/myocardial infarction (MI), and individual MACCE components death, MI and repeat revascularization at 3 years. Predictors of incomplete revascularization were explored. Results: Incomplete revascularization was found in 43.3% (388/896) PCI and 36.8% (320/870) CABG patients. Patients with complete revascularization by PCI had lower rates of MACCE (66.5 versus 76.2%, P<0.001), the composite safety endpoint (83.4 versus 87.9%,P=0.05) and repeat revascularization (75.5 versus 83.9%, P<0.001), but not death and MI. In the CABG group, no difference in outcomes was seen between incomplete and complete revascularization groups. Incomplete revascularization was identified as independent predictor of MACCE in PCI (HR=1.55, 95% CI 1.15-2.08,P=0.004) but not CABG patients. Independent predictors of incomplete revascularization by PCI were hyperlipidaemia (OR=1.59, 95% CI 1.04-2.42, P=0.031), a total occlusion (OR=2.46, 95% CI 1.66-3.64, P< 0.001) and the number of vessels (OR =1.58, 95% CI 1.41-1.77, P< 0.001). Independent predictors of incomplete revascularization by CABG were unstable angina (OR =1.42, 95% CI 1.02-1.98,P=0.038), diffuse disease or narrowed (<2 mm) segment distal to the lesion (OR=1.87, 95% CI 1.31-2.69,P =0.001) and the number of vessels (OR =1.70, 95% CI 1.53-1.89, P < 0.001). Conclusions: Despite the hypothesis-generating nature of this data, this study demonstrates that incomplete revascularization is associated with adverse events during follow-up after PCI but not CABG.