Abstract 4703: Delirium: A Cause for Concern Beyond the Immediate Post-operative Period
Background: Delirium is a common and increasing neurological complication following cardiac surgery, and may be associated with increased morbidity and mortality. Research has focused on potential causes of delirium, with little attention to sequelae.
Hypothesis: Peri-operative delirium is associated with poorer outcomes post coronary artery bypass grafting (CABG).
Methods: Peri-operative data from one center were collected prospectively on all isolated CABG cases 1995–2006. Delirium was defined using the Society of Thoracic Surgeons definition: short-term mental disturbance marked by confusion, illusions and cerebral excitement. Patient characteristics were compared between those who became delirious post-operatively and those who did not. The outcomes of interest were long-term all-cause mortality, hospital admission for stroke, and in-hospital mortality, examined by multivariate analysis.
Results: Of 8474 patients, 496 (5.8%) developed post-operative delirium; there were 229 in-hospital deaths (2.7%). At baseline, patients who developed delirium were more likely to be older and have a greater burden of comorbid illness. Delirium was an independent predictor of perioperative stroke (OR 1.96, 95%CI 1.22–3.16), but was not associated with in-hospital mortality (OR 0.81, 95%CI 0.49 –1.34). Delirious patients had a median post-operative hospital stay of 12 days (Interquartile Range (IQR) 8 –21) versus 6 days (IQR 5– 8) for the non-delirious. Median follow-up time was 3.1 years (IQR 1.0 –5.8). Adjusted five-year survival was 79.9% for patients with delirium and 85.6% for non-delirious patients; adjusted five-year freedom from hospital admission for stroke was 93.1% and 95.4% respectively. Delirium was identified as an independent predictor of all-cause mortality (HR 1.52, 95%CI 1.29 –1.78) and hospital admission for stroke (HR 1.54, 95%CI 1.10 –2.17).
Conclusion: There was an association between delirium and adverse outcomes post-CABG that persisted beyond the immediate peri-operative period. Patients with delirium appear to have increased long-term risk of death and stroke. Given the advancing age and rising rates of delirium in the CABG population, the prevention and management of delirium need to be addressed.