Background: Depression is associated with mortality in several cardiovascular populations, but has not been evaluated in patients undergoing cardiac valve surgery. Because identifying nonsurgical mediators of survival is important for accurate risk adjustment and the development of interventions to improve outcomes of care, we evaluated the hypothesis that depression predicts mortality following cardiac valve surgery.
Methods: This prospective cohort study enrolled 648 patients undergoing valve surgery at 14 Veteran Administration hospitals. A preoperative mental health inventory (MHI) depression screen was performed in all patients and patients were classified as depressed or not depressed using the standard MHI cutoff score of less than or equal to 52. Multivariable logistic regression was used to evaluate the association between depression and 6-month all-cause mortality, adjusting for other clinical risk variables.
Results: Overall, 29.2% (189/648) of the patients were depressed at baseline. Depressed patients were younger, more frequently had New York Heart Association class III/IV symptoms, and more likely required emergent surgery, preoperative intravenous nitroglycerin, or intraaortic balloon pump. Unadjusted 6-month mortality was 13.2% for depressed patients compared with 7.6% for nondepressed patients (p = 0.03). In multivariable analyses, depression remained significantly associated with mortality (odds ratio 1.90; 95% confidence interval 1.07 to 3.40, p = 0.03). These findings were consistent across subgroups of patients undergoing aortic valve replacement, mitral valve replacement and valve replacement without coronary artery bypass graft.
Conclusions: Preoperative depression is an independent risk factor for mortality following cardiac valve surgery. Depression screening should be incorporated into preoperative risk stratification, and future studies are warranted to determine if preoperative or postoperative interventions to treat depression can improve outcomes.