Survival of Overweight Patients After Coronary Artery Bypass Surgery. Does the «Obesity Paradox» Play a Role?

Although excessive body mass and obesity are considered risk factors of a number of diseases and conditions numerous results of studies evidence for the existence of the "obesity paradox"--higher long-term survival of overweight and obese patients. Aim of this study was to elucidate impact of body mass index (BMI) on postoperative mortality and long-term survival of patients after coronary artery bypass grafting (CABG).The study was conducted on the basis of register of patients with ischemic heart disease who had undergone CABG with or without correction of valvular defects and/or resection of left ventricular (LV) aneurism during the period from 2000 to 2009 in the Chelyabinsk Interregional Cardiosurgical Center. Duration of follow-up was 1 to 10 years (mean--2.3 ± 2.4 years). The patients were divided into groups in dependence on BMI. Multifactorial logistic regression analysis of association of BMI and hospital mortality was carried out with adjustment for age, sex, arterial pressure, presence of diabetes mellitus (DM), chronic obstructive pulmonary disease, LV aneurism, LV ejection fraction, and character of involvement of vessels. Long term survival was studied using Cox's regression model.Compared with group of patients with normal BMI DM and arterial hypertension were more often registered among patients with excessive body mass and obesity. Elevated body mass was not an independent factor of risk of postoperative and lower long-term survival. There was a tendency to lower survival among patients with BMI > 35 rg/m2.Results of this study evidence for the absence of proof of negative impact of excessive BMI on hospital mortality and long term survival.