Effect of body mass index on early outcomes of coronary artery bypass grafting

To assess the impact of body mass index on early outcomes of coronary artery bypass grafting in terms of morbidity and mortality. This retrospective comparative study was conducted at Chaudhry Pervaiz Elahi Institute of Cardiology, Multan, Pakistan, and comprised data of patients who underwent isolated coronary artery bypass grafting from December 2007 to December 2015. Analysis of variance and chi-square test were used for analysis of groups formed on the basis of body mass index. SPSS 20 was used for data analysis. Of the 2,366 patients, 830(35.1%) had normal body mass index, 1,024(43.3%) were overweight, 402(16.9%)were obese and 110(4.6%) were morbidly obese. The overall mean age was 55.82±9.58 years. The mean age of morbidly obese patients was significantly lower (p=0.02). Additive euro score was high in patients with normal body mass index (p=0.006). Post-op creatine kinase muscle and brain MB levels and incidence of peri-operative myocardial infarction was significantly high in obese and morbidly obese groups (p=0.002 and p=0.01, respectively). Hospital stay time was significantly longer in obese and morbidly obese patients (p=0.01). The incidence of post-operative complications was the same in all groups (p>0.05). Operative mortality was also the same between the groups (p=0.58). Higher body mass index was associated with increased risk of short-term morbidity in terms of myocardial infarction after surgery and increased length of hospital stay. Our study did not support the concept of obesity paradox.