Background: An increasing proportion of patients undergoing coronary artery bypass grafting (CABG) are obese and are thought to carry a higher mortality and morbidity in association with surgery, but data on whether health-related quality of life (QOL) improves similarly after CABG in obese and non-obese patients are limited. We assessed in detail the effect of obesity on changes in health-related QOL (RAND-36 Health Survey) during the first year following CABG.
Methods: Comprehensive data on 508 CABG patients were prospectively collected. One hundred patients (19.7%) were categorized as obese (body mass index >or= 30 kg/m(2)). The RAND-36 Health Survey was used as an indicator of quality of life. Assessments were made preoperatively and repeated 12 months later.
Results: The obese group fared significantly worse than the non-obese group with regard to the likelihood of superficial wound infection (19.0% versus 7.1%, P < 0.001), impaired renal function (31.7% versus 14.4%, P = 0.01), and required on average 2 days longer in hospital (P < 0.05). The incidence of mediastinitis was not significantly higher among the obese patients (2.0% versus 1.2%, P = 0.55), and they less frequently needed postoperative red cell transfusions (29.0% versus 44.9%, P = 0.004). The obese improved significantly (P < 0.001) in 7, and the non-obese (P < 0.001) in all 8 RAND-36 dimensions. Physical Component Summary and Mental Component Summary scores on the RAND-36 improved significantly (P < 0.001) in obese as well as in non-obese patients.
Conclusions: Although obese patients differ from non-obese patients in that they had inferior QOL before and in the year following CABG, they gain a similar improvement in QOL 1 year after surgery compared with non-obese patients. Excluding superficial wound infection, transient impaired renal function, and slightly longer hospital stay, obesity does not significantly increase the risk of other adverse outcomes during the first year following CABG.