Long-term outcomes in non-diabetic patients with metabolic syndrome undergoing revascularization for multi-vessel coronary artery disease

Aim The influence of metabolic syndrome (MS) on long-term mortality and morbidity in multi-vessel coronary artery disease (MV-CAD) is unclear. We studied the impact of MS on long-term outcomes in non-diabetic patients (NDM) with MV-CAD undergoing coronary revascularization in the Bypass Angioplasty Revascularization Investigation (BARI) trial and registry. Methods BARI trial and registry patients were separated into those with diabetes (DM) and those without. NDM fulfilling the NCEP definition of MS were identified. Ten year follow-up data were obtained on mortality, MI and development of diabetes. The data were analyzed using Cox proportional hazard modeling. Results In the BARI trial and registry 2962 NDM were identified. Of those, 510 patients had 3 or more components of the BARI-modified NCEP definition for MS, while 445 patients had 2 components of the definition and were classified as the “mixed group”. Compared to patients without MS, both MS group (RR = 3.2, p < 0.0001) and the mixed group (RR = 1.9, p = 0.02) had a higher incidence of DM over the 10-year follow-up. Type 2 DM was found to be highly associated with 10-year mortality (RR = 1.65, p < 0.0001). However, there was no statistically significant difference in the rate of death or MI at 5 and 10 years between NDM with or without MS. In multivariate analysis, the presence of MS was not associated with 10-year mortality in the BARI population (RR = 0.93, p = 0.62). Conclusion In this BARI follow-up study, we have affirmed the role of MS in predicting the development of diabetes in NDM at baseline. The 10-year risk of mortality and MI was not greater in NDM with MS who had MV-CAD and underwent revascularization, compared to patients without MS. Further studies to evaluate MS patients with MV-CAD undergoing coronary revascularization are warranted.