Modified Frailty Index as an Indicator for Outcomes After Lower Extremity Open Revascularization

Abstract

The 5-factor frailty index (mFI-5) is a standardized score that has been used as a reliable tool in predicting outcomes after surgery. The purpose of this study was to evaluate the performance of the mFI-5 after lower extremity endovascular revascularization (LEOR). The American College of Surgeons' National Surgical Quality Improvement Program Database was retrospectively analyzed for patients undergoing LEOR between 2015 and 2019. Outcomes were assessed using univariate analysis (Mann-Whitney, univariate logistic regression, and Cochran-Armitage test) and multivariate logistic regression analysis. There were 13,210 LEOR performed between 2015 and 2019 that were identified from the National Surgical Quality Improvement Program database. Mean age was 68 ± 10.96 years and 4175 (31.6%) were female. Overall, 8177 procedures (61.9%) were elective and 9398 (71.1%) were performed for chronic limb-threatening ischemia (CLTI). The 30-day mortality was 1.7%. Univariate analysis demonstrated that a mFI-5 score greater than 0.6 was associated with higher rates of prolonged hospital stay more than 7 days (34.4% vs 17.7%; P < .001; reference mFI-5 = 0), readmission (23.4% vs 11.1%; P < .001), reoperation, (19.5% vs 15.1%; P < .001), myocardial infarction (5.0% vs 1.8%; P < .001), reintubation (2.5% vs 0.5%; P < .001), acute renal failure (91.1% vs 0.2%; P < .001), 30-day mortality (3.9 % vs 1.0%; P < .001), and wound infection (14.2% vs 9.7%; P < .001). Lack of beta blocker use, higher age, CLTI indication for surgery, nonelective surgeries, tibial target, and mFI-5 were all associated with increased 30-day mortality. Multivariate logistic regression (Table) showed that mFI-5 remained as a significant predictor with mFI-5 of greater than 0.6 predicting a more than twice higher odds for 30-day mortality (odds ratio [OR], 2.324; P = .006), with age (OR, 6.384; P < .001), CLTI Indication (OR, 2.617; P < .001) and nonelective procedures (OR, 1.865; P < .001) also showing increased risk for mortality. For patients undergoing LEOR, higher mFI-5 was associated with increased hospital use, 30-day mortality, and 30-day readmission. The mFI-5, an easily calculated tool, may assist to identify patients at high risk for inferior outcomes. The mFI-5 may be useful for preoperative risk stratification and predicting mortality, and 30-day readmission for patients undergoing LEOR.TableMultivariate analysis of factors affecting 30-day mortality after lower extremity endovascular revascularization (LEOR)ORP valueAge: 18-59 (ref) 60-691.951.022 70-793.423<.001 ≥806.384<.001mF5: 0 (ref) 0.21.221.482 0.41.133.666 0.6-1.02.324.006Sex: female (ref male)0.915.544Race: other/unknown (ref White)0.946.691Use of beta blocker0.764.076Anatomical high risk0.943.681Physiological high risk (excluded owing to collinearity)Indication: CLTI (ref asymptomatic/claudication)2.617<.001Nonelective1.865<.001Procedure: tibial (ref nontibial target)1.015.917Procedure: prosthetic (ref nonprosthetic)1.110.458C-statistic0.749CLTI, Chronic limb-threatening ischemia; mF5, 5-factor frailty index; OR, odds ratio. Open table in a new tab