Atrial fibrillation as a nonpsychiatric predictor of delirium after cardiac surgery: a pilot study

Preoperative atrial fibrillation (AF) increases the risk of cardiac surgery and the occurrence of postoperative complications, including arrhythmias, low-output syndrome, delirium, and death. The aim was to evaluate its direct influence on prognosis of patients subjected to cardiac surgery.

This is a pilot study of the CODACS trial (COnsciousness Disorders After Cardiac Surgery). Two hundred sixty patients admitted for open-heart surgery were prospectively included in the study. Preoperative AF was diagnosed on the basis of multiple electrocardiographic examinations and confirmed by 24-h Holter monitoring. Diagnosis of delirium following surgical intervention was based on DSM-IV criteria.

Preoperative AF was diagnosed in 23 patients (8.8%): in 15 patients in the nondelirious group (7%) and 8 (27.0%) in the delirious group. Preoperative AF was an independent predictor of postoperative delirium (p<0.001), increasing its risk of occurrence over sevenfold (OR=7.2). AF also increased the risk of such postoperative complications as supraventricular arrhythmia (AF: 78.3% vs. non-AF: 22.8%, p<0.001), stroke (8.7% vs. 1.3%, p<0.001), and low-output syndrome (21.7% vs. 17.3%, p=0.033) and worsened prognosis, significantly increasing the risk of death (8.7% vs. 0.8%, p<0.001).

Preoperative AF was an independent risk factor of postoperative delirium (OR=7.2). It was also associated with significantly worse postoperative outcome (supraventricular arrhythmia, stroke, low-output syndrome, and risk of death). These results and data from available studies suggest that preoperative AF should be considered as an important predictor of postoperative outcome. This problem should be the subject of future research to establish beneficial treatment options.