Impact of postoperative delirium on long-term neurologic and neuropsychiatric outcome after cardiac surgery or percutaneous valve replacement-a prospective observational study

Background

Patients undergoing cardiac surgery or percutaneous valve replacement may experience long-term neurologic and neuropsychiatric complications. The impact of postoperative delirium (POD) on these long-term complications remains controversial. We intended to illustrate the neurological and neuropsychiatric outcome associated with the occurrence of POD in patients undergoing elective cardiac surgery or percutaneous valve replacement.

Methods

We included 179 patients who underwent elective cardiac surgery or percutaneous valve replacement. Patients were evaluated postoperatively for delirium status. Neurological (score A) and neuropsychiatric (score B) outcomes were assessed using a structured examination protocol and interview at 1 year postoperatively and combined into a composite neurological and neuropsychiatric score (score A + B). Cognitive function was examined using the Montreal Cognitive Assessment (MoCA). Depression, fatigue and quality of life were assessed using the Beck's Depression Inventory (BDI), the Fatigue Impact Scale (FIS) and the Short-Form Health Survey (SF-12). Clinical outcome was assessed using the Barthel-Index (BI) and Frailty Index (FI). All data were collected prospectively.

Results

One year after cardiac surgery or percutaneous valve replacement, a high number of patients suffered from neurological and neuropsychiatric symptoms with depressive symptoms (n = 36, 20.1%) and symptoms of fatigue (n = 72, 40.2%). Multivariable regression analysis showed that POD was associated with higher values on the A + B composite score, indicating worse neurological and neuropsychiatric outcome (POD status: b:1.172; 95%-CI, 0.070-2.273, p = 0.037; age: b:0.134; 95%-CI, 0.086-0.182, p < 0.001; NYHA classification at 1 year: b:1.998; 95%-CI,1.169-2.828, p < 0.001; rehospitalization b:1.786; 95%-CI, 0.640-2.932, p = 0.002). Patients with POD had lower postoperative MoCA scores (p = 0.001) and lower scores on both the SF12 Physical (p = 0.022) and the SF12 Mental Component Summary (p = 0.048). POD was not associated with depressive symptoms (p = 0.855), fatigue (p = 0.122) or rehospitalization (p = 0.379).

Conclusions

POD in patients undergoing cardiac surgery or percutaneous valve replacement was independently associated with worse long-term neurological and neuropsychiatric outcome. POD may be a relevant prognostic marker indicating the need for specific follow-up services, whereas other clinical parameters were not predictive of outcome.