Physical performance and risk of postoperative delirium in older adults undergoing aortic valve replacement

Background: Delirium is a major risk factor for poor recovery after surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR). It is unclear whether preoperative physical performance tests improve delirium prediction. Objective: To examine whether physical performance tests can predict delirium after SAVR and TAVR, and adapt an existing delirium prediction rule for cardiac surgery, which includes Mini-Mental State Examination (MMSE), depression, prior stroke, and albumin level. Design: Prospective cohort, 2014–2017. Setting: Single academic center. Subjects: A total of 187 patients undergoing SAVR (n=77) or TAVR (n=110). Methods: The Short Physical Performance Battery (SPPB) score was calculated based on gait speed, balance, and chair stands (range: 0–12 points, lower scores indicate poor performance). Delirium was assessed using the Confusion Assessment Method. We fitted logistic regression to predict delirium using SPPB components and risk factors of delirium. Results: Delirium occurred in 35.8% (50.7% in SAVR and 25.5% in TAVR). The risk of delirium increased for lower SPPB scores: 10–12 (28.2%), 7–9 (34.5%), 4–6 (37.5%) and 0–3 (44.1%) (p-for-trend=0.001). A model that included gait speed <0.46 meter/second (OR, 2.7; 95% CI, 1.2–6.4), chair stands time ≥11.2 seconds (OR, 3.5; 95% CI, 1.0–12.4), MMSE <24 points (OR, 2.9; 95% CI, 1.3–6.4), isolated SAVR (OR, 5.4; 95% CI, 2.1–13.8), and SAVR and coronary artery bypass grafting (OR, 15.8; 95% CI, 5.5–45.7) predicted delirium better than the existing prediction rule (C statistics: 0.71 vs 0.61; p=0.035). Conclusion: Assessing physical performance, in addition to cognitive function, can help identify high-risk patients for delirium after SAVR and TAVR.