Type D personality is a predictor of prolonged acute brain dysfunction (delirium/coma) after cardiovascular surgery

BACKGROUND: Previous studies have shown a relationship between delirium and depressive symptoms after cardiac surgery with distress personalities linking to negative surgical outcomes. The aim of the present study is to further investigate the association between patients with Type D (distressed) personality with regards to delirium after cardiac surgery. METHODS: We conducted a consecutive-sample observational cohort pilot study with an estimated 142 patients needed. Enrollment criteria included patients aged ≥18 years who were undergoing planned cardiovascular, thoracic and abdominal artery surgery between October 2015 to August 2016 at the University of Tsukuba Hospital, Japan. All patients were screened by Type-D Personality Scale-14 (DS14) as well as the Hospital Anxiety and Depression Scale (HADS) the day before surgery. Following surgery, daily data was collected during recovery and included severity of organ dysfunction, sedative/analgesic exposure and other relevant information. We then evaluated the association between Type D personality and delirium/coma days (DCDs) during the 7-day study period. We applied regression and mediation modeling for this study. RESULTS: A total of 142 patients were enrolled in the present study and the total prevalence of delirium was found to be 34% and 26% of the patients were Type D. Non-Type D personality patients experienced an average of 1.3 DCDs during the week after surgery while Type D patients experienced 2.1 days over the week after surgery. Multivariate analysis showed that Type D personality was significantly associated with increased DCDs (OR:2.8, 95%CI:1.3–6.1) after adjustment for depressive symptoms and clinical variables. Additionally, there was a significant Type D x depression interaction effect (OR:1.7, 95% CI:1.2–2.2), and depressive symptoms were associated with DCDs in Type D patients, but not in non-Type D patients. Mediation modeling showed that depressive symptoms partially mediated the association of Type D personality with DCDs (Aroian test =0.04). CONCLUSIONS: Type D personality is a prognostic predictor for prolonged acute brain dysfunction (delirium/coma) in cardiovascular patients independent from depressive symptoms and Type D personality-associated depressive symptoms increase the magnitude of acute brain dysfunction.