Postoperative But Not Preoperative Depression Is Associated With Cognitive Impairment After Cardiac Surgery

Exploratory Analysis of Data From a Randomized Trial

Choy Lewis; Mehmet E. Dokucu; Charles H. Brown; Lauren Balmert; Nina Srdanovic; Ashwin Shaan Madhan; Sahej Singh Samra; John Csernansky; Jordan Grafman; Charles W. Hogue


BMC Anesthesiol. 2022;22(157) 

In This Article


Approximately 15% of adults in the United States suffer from a major depressive disorder leading to reduced work productivity, compromised health, and reduced survival.[1,2] The prevalence of depression is reported to be even higher in patients with cardiac diseases including those undergoing cardiac surgery where it is reported in up to 40% of patients.[3–6] Symptoms of depression at the time of surgery is associated with risk for postoperative complications, reduced functional recovery, impaired quality of life, and mortality.[3,4,6–8] Science Advisory Committee recommendations from the American Heart Association, in fact, recommend screening for depression in patients with coronary artery disease including those undergoing surgery.[9] Nonetheless, a mechanistic explanation for why pre-existing depression contributes to adverse postoperative outcomes is unclear.[10]

Perioperative neurocognitive disorders contribute to patient morbidity after cardiac surgery.[11] These disorders are manifest early after surgery as delirium or in the weeks to months later as postoperative neurocognitive dysfunction.[12] We have found that a history of depression is two to three times more common in patients developing postoperative delirium than in those without delirium.[13,14] Further, we have found an association between depression within a year of cardiac surgery and perceived cognitive difficulties.[4] Less is known, however, on the role that depression plays in neurocognitive dysfunction one month after surgery. Understanding if this link is present might provide insight into whether attenuating depressive symptoms is a plausible strategy for improving neurocognitive recovery from cardiac surgery. The aim of this study was to evaluate whether there is a relationship between depression either before or after cardiac surgery and postoperative neurocognitive dysfunction. Impairment of individual cognitive domains that comprise a composite neurocognitive outcome identifies risk for postoperative delirium in depressed patients after non-cardiac surgery even in the absence of global cognitive impairment.[15] Thus, we focus on an evaluation of domain-specific cognitive performance. We hypothesize that preoperative and/or postoperative depression is associated with reduction from baseline in domain-specific cognitive function one month after surgery compared with patients not having depression.