Relationship Between Body Mass Index and Left Main Disease: The Obesity Paradox

Background and Aims: Obesity is a well-known risk factor for development of diabetes, hypertension, and coronary artery disease. However, the obesity paradox shows that short-term outcome has been reported to be superior after revascularization in overweight patients. We conducted this study to examine this theory in patients who were candidates for coronary artery bypass graft and to determine if there is a relationship between obesity and the severity of coronary artery involvement and left main disease in Iranian patients. Methods: A total of 15,550 patients who had undergone isolated coronary artery bypass graft were studied retrospectively. All medical records of the aforementioned patients were derived from our hospital surgery data bank. Preoperative angiography was used for angiographic data. Results: After adjusting for confounding variables, we still found a significant relationship with higher BMI and lower prevalence of left main disease. Conclusions: We found that despite a higher prevalence of hypertension, diabetes mellitus, and dyslipidemia, overweight and obese patients who were candidates for coronary artery bypass graft surgery were significantly less likely to have left main disease according to preoperative angiography. This study suggests that obese patients are more likely to be referred for coronary artery bypass graft in earlier stages of coronary involvement.