Changes in cardiac and cognitive function and self-reported outcomes at one year after coronary artery bypass grafting

Abstract

Although health status after coronary artery bypass grafting improves at the group level, individual outcomes demonstrate variation. We aimed to evaluate relative importances of changes in cardiac and cognitive function and symptom status regarding physical and mental health at 1 year after coronary artery bypass grafting. Outcomes in multivariable regression analysis (n = 86) were self-reported physical and mental health (Medical Outcomes Study 36-Item Short Form) at 12 months' follow-up, adjusting for baseline. Independent variables were change in exercise capacity (staged ergometer protocol), cognitive function (neurocognitive test battery), and self-reported improvement of angina. Graft patency was evaluated by angiography (82/86 patients). After surgery, health status was comparable to the age- and sex-matched population norm. Improvement of angina was associated with gain in physical health in the range of 0.5 SD (beta = 0.23, P = .012). Change in observed physical exercise capacity (mean +/- SD 199 +/- 426 W x min) accounted for 9% of variance in physical health (beta = 0.42, P = .001). Positive change in cognitive function was significantly related to mental (beta = 0.52, P = .007) but not physical health. Graft occlusion (22/82 patients) was not significantly related to health status. Individual variation in objective functional performance and symptom relief is significant for self-reported health status, beyond the predictive ability of preoperative health status, sex, and graft patency. Awareness of the extent and impact of outcome variation is important when counseling patients before and after coronary artery bypass grafting.