PREOPERATIVE FRAILTY PREDICTS POSTOPERATIVE LONG-TERM COGNITIVE DECLINE INDEPENDENT OF DELIRIUM

Abstract

AbstractFrailty is present in almost half of all older surgical patients. Although frailty has been associated with cognitive decline, this has not been examined in the context of surgery. It is also not known if this relationship is independent of delirium, an established risk factor for postoperative cognitive decline. We probed these questions in the Successful Aging after Elective Surgery cohort of 560 dementia-free older adults (≥70 years old) undergoing elective surgery. Frailty and delirium were measured, respectively, by the Fried Frailty Index and the Confusion Assessment Method supplemented by medical chart review. Postoperative cognitive trajectory was measured as the slope of the General Cognitive Performance (GCP) score, a composite derived from results of a neuropsychological battery administered 2–36 months post-surgery. 64 (12%) of patients were robust, 280 (56%) were pre-frail, and 160 (32%) were frail. Delirium occurred in 134 patients (24%) overall. Compared to the rate of GCP decline among robust patients, decline was steeper by -0.47 points/year (95% CI -0.83, -0.14, p=.005) among pre-frail patients and by -0.48 points/year (95% CI -0.88, -0.07, p=.02) among frail patients. This effect was independent of age, sex, and education. Notably, the known influence of delirium on cognitive decline did not account for the association between frailty and cognitive decline. These results suggest pre-frailty, frailty and delirium are independently associated with accelerated postoperative cognitive decline, with effects of similar magnitude to each other and to mild cognitive impairment. Preoperative frailty screening could identify patients at higher risk of cognitive decline after surgery.