Five-factors Modified Frailty Index role as predictors of outcomes after proximal abdominal aortic aneurysms.

Abstract

The aim of the study was to evaluate the correlation between frailty, measured by the Five-Factor Modified Frailty Index (mFI-5) and mortality and all major adverse events (MAE) in patients who underwent proximal abdominal aortic aneurysm (p-AAA) open surgery (OS). Data of all elective patients submitted to p-AAA OS from 2010 to 2021 were recorded. Primary endpoints were 30-day mortality and mid-term survival and secondary endpoints included postoperative acute kidney injury (AKI), freedom from aortic reintervention and any MAE. The impact of frailty was assessed by univariate and multivariate analysis; mid-term overall survival were estimated using Kaplan-Meier method (log-rank test). Two-hundred twenty-one patients (197 male, 24 female; aged 72.2±7.4) were included. Thirty-seven (16.4%) were octogenarians (>80 years). The mFI-5 was assessed in the entire group: mean mFI-5 was 0.29±0.12. One-hundred patients (100/221, 45.25%, 91:9 male-to-female ratio) were defined "frail" considering the mFI-5 cut-off >0.25. At univariate analysis a correlation was found between mFI-5>0.25 and mid-term mortality (Pearson correlation [r] 0.280, P<0.001) and AKI (r=0.146, P=0.030). No correlation with 30-day mortality was found (P not significant). At multivariate analysis mFI-5>0.25 increased the risk for midterm mortality (odds ratio 3.32, P=0.021) and postoperative AKI (OR 2.09, P<0.001). The effect of mFI-5>0.25 on mid-term mortality persisted after adjustment for age (P<0.001). Survival was estimated with Kaplan-Meyer method (mean follow-up of 52.7 months, 95% CI: 48.6-56.8); 68 (30.7%) deaths were recorded: 23 among non-frail patients (19.0%) and 45 among frail patients (45/100, 45%, P<0.001). These findings suggest that mFI-5 is a tool capable to identify "frail" patients, who appear to be at increased risk of postoperative AKI and mid-term mortality, but not 30-day mortality. Five-factor modified Frailty Index assessment is simple, fast and can be widely applied in surgical practice to perform appropriate risk stratifications.