Impact of chronic kidney disease on health-related quality-of-life improvement after coronary artery bypass surgery

Background: Little is known about the impact of chronic kidney disease (CKD) on health-related quality-of-life outcomes after coronary artery bypass grafting (CABG). Methods: Our objective was to examine the changes in physical function (PF) and mental health (MH) 6 months after CABG in 1055 patients with and without CKD. The primary end points were mean change in score and status of "improved" or "worsened" in both PF and MH subscales of the Medical Outcomes Trust Short Form 36-Item Health Survey from baseline to 6 months after CABG, stratified by CKD stage (0-5). Results: Absolute PF and MH scores at baseline and at 6 months varied by renal impairment level. Patients with severe CKD (stages 4-5) had a mean (SD) decrease in PF score at 6 months of 3 (3) compared with increases in the rest of the cohort (P<.001). After adjustment for baseline score, 21% of patients with advanced CKD experienced worsened PF scores, compared with 0% of patients with stages 0 to 2 and stage 3 CKD (P<.001). In contrast to PF scores, patients with and without CKD had similar improvements in mean MH scores at 6 months, and patients with stages 4 to 5 CKD had the highest frequency of those with improved MH scores (77%). After adjustment, no patients experienced worsened MH scores. Conclusions: After 6 months, patients with severe CKD who underwent CABG had improvement in MH but not improvement in PF and may have had worsened PF compared with those without severe CKD. Comparable evidence regarding quality-of-life outcomes in the absence of CABG is needed to more fully inform decision making regarding patients with severe CKD and coronary artery disease.