Clinical depression, posttraumatic stress disorder, and comorbid depression and posttraumatic stress disorder as risk factors for in-hospital mortality after coronary artery bypass grafting surgery

Objective

The goal of this study was to examine the effect of clinical depression, posttraumatic stress disorder, and comorbid depression and posttraumatic stress disorder on in-hospital mortality after a coronary artery bypass grafting surgery. It is hypothesized that depression, posttraumatic stress disorder, and comorbid depression and posttraumatic stress disorder will independently contribute to an increased risk for in-hospital mortality rates after coronary artery bypass grafting surgery.

Methods

We performed a retrospective analysis of the 2006 Nationwide Inpatient Sample database. The Nationwide Inpatient Sample database provides information on approximately 8 million US inpatient stays from about 1000 hospitals. We performed χ² and unpaired t tests to evaluate potential confounding group demographic and medical variables. Hierarchic logistic regression was used with forced order entry of depression, posttraumatic stress disorder, and comorbid depression and posttraumatic stress disorder.

Results

Deceased patients were more likely to have had depression (alive, 24.8%; deceased, 60.3%; P < .001), posttraumatic stress disorder (alive, 13.4%; deceased, 56.1%; P < .001), and cormorbid depression and posttraumatic stress disorder (alive, 7.8%; deceased, 48.5%; P < .001). After adjusting for potential confounding factors, patients with depression (odds ratio, 1.24; 95% confidence interval, 1.02–1.50), posttraumatic stress disorder (odds ratio, 2.09; 95% confidence interval, 1.65–2.64), and comorbid depression and posttraumatic stress disorder (odds ratio, 4.66; 95% confidence interval, 3.46–6.26) had an increased likelihood of in-hospital mortality compared with that seen in patients who were alive.

Conclusions

Two findings were noteworthy. First, depression, posttraumatic stress disorder, and comorbid depression and posttraumatic stress disorder are prevalent in patients undergoing coronary artery bypass grafting procedures. Second, depression, posttraumatic stress disorder, and comorbid depression and posttraumatic stress disorder increase the risk of death by magnitudes comparable with well-established physical health risk factors after coronary artery bypass grafting surgery. The implications for clinical practice and future directions are discussed.

CTSNet classification: 2, 23

Abbreviations and Acronyms: ANS, autonomic nervous system, CABG, coronary artery bypass grafting, CAD, coronary artery disease, HRV, heart rate variability, ICD-9-CM, International Classification of Diseases, 9th Revision, Clinical Modification, NIS, Nationwide Inpatient Sample, OR, odds ratio, PTSD, posttraumatic stress disorder