Metabolic syndrome predicts 10-year mortality in non-diabetic patients following coronary artery bypass surgery

Background Metabolic syndrome (MetS) is a risk factor for cardiovascular disease and mortality, but, the relationship between MetS and survival after coronary artery bypass grafting (CABG) remains unclear. Methods and Results The outcomes of patients with and without MetS were analyzed. Patients who had undergone CABG at Juntendo University Hospital between January 1984 and December 1992 were enrolled. The survival search was performed by the end of 2000. The patients were categorized by the existence of preoperative MetS using the modified American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) definition with body mass index instead of waist circumference. MetS was present in 551 (46.6%) patients and absent in 632 (53.4%). Preoperative MetS was associated with long-term poor prognosis in terms of all-cause death (hazard ratio (HR) 1.34; 95% confidence interval (CI) 1.03-1.74; p=0.028) and cardiac death (HR 2.31; 95% CI 1.36-3.92; p=0.002) in non-diabetic patients. These differences in the mortality of the 2 groups were more obvious after 10 years. However, among the patients with diabetes, the presence of MetS was not related to long-term mortality. Conclusions Preoperative MetS predicted increased all-cause and cardiac mortality, especially after 10 years, in non-diabetic patients undergoing CABG.