The effects of the metabolic syndrome on coronary artery bypass grafting surgery

The metabolic syndrome (MS) is a clustering of factors that are associated with increased cardiovascular risk. A low-grade inflammatory process acts as the underlying pathophysiology, which suggests that the MS may have a detrimental effect on coronary interventions, including coronary artery bypass grafting (CABG) surgery performed with cardiopulmonary bypass (CPB). We aimed to evaluate the effect of the MS on morbidity and mortality rates in the early postoperative period in patients undergoing CABG.

We prospectively included 152 patients (109 males and 43 females; mean age 60.1 ± 8.6 years) who underwent elective CABG on CPB between January and September 2011. Early postoperative morbidity and mortality rates were compared between subjects with and without the MS. Diagnosis of the MS was based on the American National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria.

Of the study group, 64 patients (42%) had the MS. The two groups were similar in age and gender. In the postoperative period, rates of atrial fibrillation, wound infection, pulmonary complications, and lengths of intubation, hospitalisation and intensive care unit stay were significantly higher in MS patients (p < 0.01). The MS was significantly associated with wound infection (OR 6.64, 95% CI: 1.72-25.75), pulmonary complications (OR 6.44, 95% CI: 1.58-26.33), arrhythmia (OR 5.47, 95% CI: 1.50-19.97) and prolonged intubation (OR 1.17, 95% CI: 1.05-1.32). The mortality rate was 3.1% in the MS group and 1.1% in the non-MS group, with no significant difference (p > 0.05).

The MS was associated with a higher rate of early postoperative morbidity following CABG, without having a significant effect on the mortality rate.