Adverse events after coronary artery bypass grafting in patients with preoperative metabolic syndrome: A 10-year follow-up of the Veterans Affairs Database

Introduction: Data regarding 10-year survival and adverse cardiovascular events in patients with metabolic syndrome (MET) after coronary artery bypass grafting (CABG) is limited. Methods: We compared 10-year events rates for veterans undergoing isolated CABG (January 1, 2005, to December 31, 2014, follow-up October 31, 2019) stratified by presence of metabolic syndrome (MET+) versus without (MET-). A multivariable weighted Cox model was used to analyze all-cause mortality. Competing risk analysis was used to calculate cumulative event rates for congestive heart failure, myocardial infarction, and cerebrovascular events. The Fine-Gray subhazard model was used to determine adjusted association of MET with myocardial infarction and stroke. Congestive heart failure was modeled as a recurrent-event analysis. Results: Nationally, 9615 adults (median age, 60 years; 98.9% men) underwent isolated coronary artery bypass grafting at 41 centers); among them, 3121 out of 9615 (32.5%) had MET. The prevalence of MET increased from (27.88% in 2005 to 34.02% in 2014; P = .02). MET+ group members were likely younger (median age, 63 vs 64 years; P < .01), White (72% vs 68%), and had more peripheral vascular disease (30% vs 28%; P = .04). Multivessel (72% vs 70%; P = .23) and multiarterial (4% vs 4%; P = .14) grafting was performed equally. With a median follow-up of 6.5 years, survival was similar (P = .26); however, MET was associated with higher risks for myocardial infarction (21% vs 16%; hazard ratio, 1.3; P < .01) and recurrent admissions for congestive heart failure. Conclusions: Patients with metabolic syndrome undergoing coronary artery bypass grafting have higher 10-year cardiovascular event rates.