Paper Information

This analysis included participants aged ≥ 60 years undergoing elective cardiac surgery with cardiopulmonary bypass. Serum Aβ40, Aβ42 and tTau were measured before surgery and on postoperative day one using a digital immunoassay. The primary outcome was postoperative delirium, assessed twice daily for 3 days using the Confusion Assessment Method.

Aβ40, AβR, and tTau were associated with postoperative delirium in elderly patients undergoing elective cardiac surgery. These findings suggest that postoperative delirium may be linked to pre-existing vulnerabilities shared with neurodegenerative processes along the Alzheimer's disease spectrum, offering new insights into its underlying mechanisms and potential connection to long-term cognitive decline.

Postoperative delirium developed in 12% (38/312) of participants. In adjusted analyses examining preoperative biomarkers, the odds of postoperative delirium were independently associated with Aβ40 (OR 1.44 per standard deviation increase, 95% CI 1.06-1.98; p = 0.021), AβR (OR 0.65, 95% CI 0.42-0.99; p = 0.046), and tTau (OR 1.65, 95% CI 1.01-2.68; p = 0.045). Aβ42 was statistically significant only in unadjusted analyses (OR 1.43, 95% CI 1.00-1.88; p = 0.012). In adjusted analyses examining postoperative biomarkers, the odds of postoperative delirium were independently associated with Aβ42 (OR 1.60, 95% CI 1.08-2.37; p = 0.020) and tTau (OR 1.56, 95% CI 1.09-2.23; p = 0.015).

Postoperative delirium is a significant complication in older adults undergoing cardiac surgery. This study investigated associations between serum amyloid beta (Aβ40, Aβ42), their ratio Aβ42/Aβ40 (AβR), and total tau (tTau) and postoperative delirium.