A Low Life's Simple 7 Score Is an Independent Risk Factor for Postoperative Delirium After Total Knee Arthroplasty

Background and Objectives: Postoperative delirium (PODil) is a cognitive condition characterized by sudden fluctuations in consciousness and orientation after surgery. PODil following total knee arthroplasty (TKA) is associated with prolonged hospital stays and increased morbidity. Therefore, prevention of PODil is particularly important. Life's Simple 7 score, published by the American Heart Association, is a new measure of cardiovascular health (CVH). Better CVH is associated with a lower risk of cognitive impairment. Hence, this study aimed to determine whether Life's Simple 7 score is associated with PODil following TKA. Materials and Methods: This retrospective study included 973 patients who underwent TKA between January 2015 and January 2020. Patients were divided into two groups (group I: delirium group, n = 60; group II: non-delirium group, n = 913). Demographic data, use of analgesics, surgical factors, underlying diseases, laboratory results, and Life's Simple 7 score were evaluated. Results: Significant differences were observed between the two groups for Parkinson's disease, intraoperative hypotension, preoperative duloxetine administration, and Life's Simple 7 score. In the receiver operating characteristic (ROC) curve analysis, the optimal cut-off value for Life's Simple 7 score was determined to be 8 at the maximal Youden index, with an area under the curve (AUC) of 0.82, a sensitivity of 0.92, and a specificity of 0.58. Conclusions: Lower Life's Simple 7 score is an independent risk factor for the incidence of PODil after TKA. Given its ease of measurement, Life's Simple 7 score may be a useful measure for predicting PODil and will aid in preoperative risk assessment and post-operative patient management.