The varying effects of obesity and morbid obesity on outcomes following cardiac transplantation

The purpose of this study was to compare the outcomes of patients undergoing cardiac transplantation stratified by body mass index (BMI, kg m(-2)). The Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease registry captured 220 cardiac transplantations in Alberta, Canada from January 2004 to April 2013. All recipients were stratified by BMI into five groups (BMI: < 20, 20-24.9, 25-29.9, 30-<34.9 and >= 35). Patient characteristics were analyzed by analysis of variance and chi(2) analyses. Kaplan-Meier was used to examine survival differences. Preoperative characteristics demonstrated significant increases in metabolic syndrome, prior myocardial infarction and prior coronary artery bypass graft in patients with morbid obesity. Intraoperatively, there was an increase in cardiopulmonary bypass time in patients with morbid obesity (P>0.01). Postoperative analysis revealed increased rates of early complications (<30 days), associated with a BMI 435. Long-term survival was also significantly decreased in patients with morbid obesity. Of interest, obesity (BMI, 30-34.9) was not associated with decreased survival. These findings suggest that, post-cardiac transplantation, patients who have a BMI >= 35 have lower long-term survival compared with all other BMI groups. However, patients with BMI 30-34.9 did not have significantly worse outcomes and should not be excluded for heart transplantation based on BMI.