The effect of obesity on long-term survival and health-related quality of life after coronary artery bypass grafting

OBJECTIVE: The proportion of obese patients undergoing coronary artery bypass graft (CABG) surgery is increasing. In this study, our main objective was to assess the effect of obesity on long-term mortality and changes in quality of life (QoL) after GABG. MATERIALS AND METHODS: Data of 508 patients who underwent isolated GABG were prospectively collected. RAND-36 Health Survey (RAND-36) was used as an indicator of QoL. BMI was used to assess obesity, and the analysis was based primarily on two patient groups: BMI less than 30 kg/m (408 patients) and BMI of at least 30 (100 patients). All assessments were made preoperatively and repeated 1 and 12 years after CABG surgery. The follow-up of the cohort was complete in 95 and 84% of the alive patients at 1 and 12 years, respectively. RESULTS: Thirty-day, 1-year, and 10-year survival rates were 99.0, 97.0, and 78.0%, respectively, in the obese and 98.0, 96.8, and 79.2%, respectively, in the nonobese group. Obese showed significant (P<0.05) improvements only in four and nonobese in seven of eight RAND-36 dimensions of QoL. In both obese and nonobese patients, improved RAND-36 physical component summary and mental component summary scores were seen in comparison with the preoperative values. Yet, obese patients had a more pronounced diminution in their physical component summary and mental component summary scores, whereas nonobese patients maintained their physical and mental health status better. CONCLUSION: Despite an on-going decline in 12 years after the CABG, both patient groups showed improvements in their health status in comparison with preoperative values. Obese patients gained less benefit in terms of QoL dimension, but there was no significant difference in overall mortality in the long-term follow-up.