The Modified Frailty Index-11 is a Poor Predictor of One-Year Mortality and Morbidity after Ruptured Abdominal Aortic Aneurysm Repair.

Abstract

Objective: Previous research has shown that frailty, using the modified frailty index (mFI-11), does not correlate with 30-day outcomes after repair of a ruptured abdominal aortic aneurysm (rAAA). However, there are no studies to date investigating whether mFI-11 is associated with longer-term mortality and morbidity after rAAA repair. The aim of this study was to evaluate whether mFI-11 can be used as a risk assessment tool for predicting one-year mortality and morbidity in patients undergoing both open and endovascular rAAA repair.

Methods: We conducted a retrospective analysis of all patients undergoing rAAA repair at a single tertiary care center from January 2011 to November 2022. Frailty was assessed for each patient using the mFI-11, a validated frailty metric based on the Canadian Study of Health and Aging, and was defined as an mFI-11 ≥0.27. The primary outcome was one-year mortality. Logistic regression, cox regression, and receiver operating characteristic (ROC) curves were used to assess mFI-11 with one-year morbidity and mortality. Kaplan-Meier analysis was used to compare rates of survival. Categorical and continuous data were compared using χ² and Student's t-tests, respectively. For all tests, a p-value of <0.05 was considered statistically significant.

Results: Seventy-eight patients were identified during the study period (35 frail vs. 43 non-frail) with a median follow up of 7 months (6 months frail vs. 10 months non-frail) and a one-year mortality rate of 40% overall (49% frail vs. 33% non-frail, p=0.10). Multivariable analysis showed no correlation between frailty and reintervention (odds ratio 1.6 [95% confidence interval 0.1-27.6], p=0.75), dialysis dependence (0.8 [0.1-9.2], p=0.83), home oxygen use (1.6 [0.2-13.0], p=0.6), and dependent mobility (0.8 [0.12-4.7], p=0.79). The area under the ROC curve (AUC) for mFI-11 was 0.58 for one-year mortality (p=0.2). Kaplan Meier analysis showed no difference in rates of survival between frail and non-frail patients (p=0.29).

Conclusions: MFI-11 was not predictive of one-year outcomes after open or endovascular rAAA repair. Other metrics are needed to more accurately assess long term risk to enable better patient and family counseling after repair of rAAA.