The association between obesity and graft failure after coronary artery bypass grafting has not been previously investigated.We pooled individual patient data from randomized clinical trials with systematic post-operative coronary imaging to evaluate the association between obesity and graft failure at the individual graft and patient levels. Penalized cubic regression splines and mixed-effects multivariable logistic regression models were performed.Six trials comprising 3,928 patients and 12,048 grafts were included. The median time to imaging was 1.03 (IQR, 1.00-1.09) years. By body mass index (BMI) category, 800 (20.4%) patients were normal weight (BMI 18.5-24.9), 1,668 (42.5%) were overweight (BMI 25-29.9), 983 (25.0%) were obesity class 1 (BMI 30-34.9), 344 (8.8%) were obesity class 2 (BMI 35-39.9), and 116 (2.9%) were obesity class 3 (BMI 40+). As a continuous variable, BMI was associated with reduced graft failure (adjusted odds ratio [aOR] 0.98 [95% CI, 0.97-0.99]) at the individual graft level. Compared to normal weight patients, graft failure at the individual graft level was reduced in overweight (aOR 0.79 [95% CI, 0.64-0.96]), obesity class 1 (aOR 0.81 [95% CI, 0.64-1.01]), and obesity class 2 (aOR 0.61 [95% CI, 0.45-0.83]) patients, but not different compared to obesity class 3 (aOR 0.94 [95% CI, 0.62-1.42]) patients. Findings were similar, but did not reach significance, at the patient level.In a pooled individual patient data analysis of randomized clinical trials, BMI and obesity appear to be associated with reduced graft failure at one year after coronary artery bypass grafting.
