[No significant association between obesity and long-term outcome of coronary artery bypass grafting]

Our objective was to investigate long-term outcomes of obese patients undergoing coronary artery bypass grafting (CABG) in Iceland.

A retrospective analysis on 1698 patients that underwent isolated CABG in Iceland between 2001-2013. Patients were divided into four groups according to body mass index (BMI); Normal=18.5-24.9kg/m2 (n=393), ii) overweight=25-29.9 kg/m2 (n=811), iii) obese=30-34.9 kg/m2 (n=388) and iv) severely obese ≥35kg/m2 (n=113). Thirty-day mortality and short-term complications were documented as well as long-term complications that were pooled into major adverse cardiac and cerebrovascular events (MACCE) and included myocardial infarction, stroke, repeated CABG, percutaneous coronary intervention with or without stenting, and death. After pooling the study groups, survival and freedom from MACCE plots (Kaplan- Meier) were generated and Cox regression analysis used to identify predictive factors of survival. Average follow-up time was 5.6 years.

Severely obese and obese patients were significantly younger than those with a normal BMI, more often males with identifiable risk factors of coronary artery disease (CAD) and a lower EuroSCORE II (1.6 vs. 2.7, p=0.002). The incidence of major early complications, 30-day mortality (2%), long-term survival (90% at 5 years, log-rank test p=0.088) and MACCE-free survival (81% at 5 years, log-rank test p=0.7) was similar for obese and non-obese patients. BMI was neither an independent predictor for long-term (OR: 0.98 95%-CI: 0.95-1.01) nor MACCE-free survival (OR: 1.0 95%-CI: 0.98-1.02).  Conclusions: Obese patients that undergo CABG in Iceland are younger and have an increased number of risk factors for coronary disease when compared to non-obese patients. However, BMI neither predicted long-term survival or long-term complications. The outcomes following CABG in obese patients are good in Iceland.