Increased Frailty Associated with Higher Long-Term Mortality after Major Lower Extremity Amputation

Background: Frailty assessments have been incorporated into preoperative planning for surgery in the elderly population. Frailty in patients undergoing lower extremity amputation has been associated with increased short-term mortality. We compared 2 frailty scores, modified Frailty Index (mFI) and Risk Analysis Index (RAI), to evaluate the short- and long-term mortality stratified by frailty status after lower extremity amputation. Methods: A retrospective review at a single Veterans Affairs Medical Center was performed for all patients with peripheral vascular disease that underwent an above or below the knee amputation from 2014 to 2019. Preoperative variables were obtained to calculate the mFI and RAI frailty scores. The frailty scoring systems were used to separate the patients into 3 cohorts: non-frail (mFI <0.45, RAI <20), frail (mFI 0.45-0.55; RAI 20-32), and very frail (mFI >0.55, RAI >32). The frailty groups with each scoring system were compared for 30-day outcomes (readmission, reoperation, adverse events, length of stay) and short- and long-term mortality. Results: A total of 298 patients underwent lower extremity amputation. The number of non-frail patients was 98 (RAI) and 102 (mFI); frail patients 99 (RAI), and 123 (mFI); very frail patients 101 (RAI) and 73 (mFI). For the 30-day outcomes, only length of stay (mFI) was associated with increasing frailty. The short- and long-term mortality was associated with a worse survival with increasing frailty. At 1-year, the mortality by RAI was non-frail 8%; frail 24%, very frail 43% (P < 0.001); the mortality by mFI was non-frail 16%, frail 24%, very frail 41% (P < 0.001). Conclusions: Preoperative frailty scoring systems identify patients with worse short- and long-term mortality for lower extremity amputation. Frailty scoring should be considered as a screening tool for patients with peripheral vascular disease undergoing lower extremity amputation because of the high rate of frail and very frail patients. The frailty status may provide a more patient-centered approach to counsel patients and their families on the risks and benefits of amputation.