Clinically Optimal Neuropsychological Tests for Postoperative Cognitive Dysfunction in Heart Valve Surgeries

Background: Postoperative cognitive dysfunction (POCD) is widely recognized and reported, but the lack of a uniform definition makes it difficult to evaluate its clinical impact. The aim of this study is to establish the optimal neuropsychological tests and definition of POCD relevant to clinical outcomes in heart valve surgeries. Methods and Results: Between June 2015 and December 2019, 315 patients undergoing elective heart valve surgeries (age >= 65 years) were enrolled. The Mini-Mental Status Examination, Montreal Cognitive Assessment (MoCA), and the Trail Making Test A and B were performed to evaluate cognitive function. Clinical endpoints were defined as readmission and death. The postoperative readmission and death rate were 17% and 3% (54/315 and 8/315; follow-up 266-1,889 days). By multivariable Cox hazard analysis, Short Physical Performance Battery (adjusted hazard ratio [HR]: 0.84, 95% confidence interval [CI]: 0.49-0.98, P=0.001), MoCA change rate (adjusted HR: 0.64, 95% CI: 0.01-1.22, P=0.024), and intensive care unit stay (adjusted HR: 0.55%, 95% CI: 0.99-1.12, P=0.054) were detected as independent risk factors for combined events. The cutoff value was -12% in the change rate of MoCA. Conclusions: MoCA was the only neuropsychological test that predicted the clinical impact on complex events and has the potential to define POCD.