LAUSR

Background Cardiac surgery in frail patients has been reported to be associated with increased mortality and morbidity but may improve functional status of frail patients. Few studies have investigated the impact of cardiac surgery on the trajectory of postoperative frailty. We hypothesized that cardiac surgery in frail patients would improve frailty postoperatively. Method This study included 71 patients over 65 years old who were scheduled for cardiac surgery via sternotomy or thoracotomy. Frailty was prospectively evaluated using the Kihon Checklist (KCL) at 1 and 3 months postoperatively. Patients were divided into three groups based on the preoperative KCL score: nonfrail, prefrail, and frail. The interaction between the degree of preoperative frailty and the trajectory of postoperative KCL scores was assessed. Results The KCL score changed significantly over time ( P  < 0.001), and the KCL score trajectory differed significantly according to the degree of preoperative frailty ( P for interaction = 0.003). In the frail group, the KCL score was significantly lower 3 months postoperatively than preoperatively (median 8, interquartile range [5, 9] versus median 9, interquartile range (9, 13), P  = 0.029). Conclusion The trajectory of postoperative KCL scores differed significantly depending on the degree of preoperative frailty. At 3 months after cardiac surgery, the KCL score of frail patients was significantly improved, while that in nonfrail patients was significantly deteriorated.