Effects of Metabolic Syndrome with or without Obesity on Outcomes after Coronary Artery Bypass Graft. A Cohort and 5-Year Study

BACKGROUND: Metabolic syndrome (MetS) and obesity are risk factors for cardiovascular disease, however, it remains unclear about effects of MetS with or without obesity on perioperative and long-term morbidity and mortality after coronary artery bypass graft (CABG). METHODS: An observational cohort study was performed on 4,916 consecutive patients receiving isolated primary CABG in Fuwai hospital. Of all patients, 1238 patients met the inclusion criteria and were divided into three groups: control, MetS with obesity and MetS without obesity (n = 868, 76 and 294 respectively). The patient's 5-year survival and major adverse cerebral and cardiovascular events (MACCE) were studied. RESULTS: Among all three groups, there were no significant differences in in-hospital postoperative complications, epinephrine use, stroke, ICU stay, ventilation time, atrial fibrillation, renal failure, coma, myocardial infarction, repeated revascularization, and long-term stroke. The patients in MetS without obesity group were not associated with increased perioperative or long-term morbidities and mortality. In contrast, the patients in MetS with obesity group were associated with significant increased perioperative complications including MACCE (30.26% vs. 20.75%, 16.7%, p = 0.0074) and mortality (11.84% vs. 3.74%, 3.11%, p = 0.0007) respectively. Patients in MetS with obesity group was associated with significantly increased long-term of MACCE (adjusted OR:2.040; 95%CI:1.196-3.481; P＜0.05) and 5-years of mortality (adjusted HR:4.659; 95%CI:1.966-11.042; P＜0.05). CONCLUSIONS: Patients with metabolic syndrome and obesity are associated with significant increased perioperative and long-term complications and mortality, while metabolic syndrome without obesity do not worsen outcomes after CABG.