Author + information
- Jared Cline,
- Joshua Perese,
- David Shavelle,
- Vincent Rowe,
- David Armstrong,
- Jorge Caro and
- Leonardo Clavijo
Critical limb ischemia (CLI) is an advanced stage of peripheral arterial disease in which insufficient blood flow to an affected extremity results in ischemia, frailty, and adverse outcomes. Frailty is increasingly used to preoperatively risk-stratify patients and has become an important prognostic marker for mortality in cardiovascular (CV) patients. The aim of this study was to assess the utility of the Vascular Quality Initiative (VQI) and modified Frailty Index (mFI) frailty scales in patients with CLI by correlating frailty indices to adverse in-hospital events.
This study retrospectively examined frailty in 494 patients with CLI who presented to LAC+USC (January 2012-June 2017). Patients were analyzed on 15 criteria unique to the VQI and mFI scales and separated into 10 and 11 categories respectively. The frailty index was calculated by scoring 1 point for a positive category, summing up the positive value categories and dividing by 10, yielding a ratio between 0 and 1. The index was classified as a VQI-derived frailty index ≥ 0.3 = “frail”, FI ≤ 0.08 = “non-frail” and 0.08≤FI ≥0.3 = pre-frail. The mFI scale was performed in the same manner and patients were separated: mFI ≤ 0.08 = “non-frail”, those with mFI ≥ 0.25 = “frail”, 0.08≤ mFI≥0.25 = “pre-frail”. Once these patients were separated, the indices were correlated to rates of death, amputation, and CV endpoints using Chi Square, ANOVA and Student t-tests.
Using the mFI, planned amputations occurred in 19.5% of frail versus 2.5% of pre-frail patients (p = 0.008). Frailty status calculated with the VQI index correlated with death and planned amputation: frail patients experienced 23% planned amputations versus 4% in non-frail and 16% in pre-frail (p = 0.025). Death only occurred in frail patients (p = 0.034). Unplanned amputation showed no correlation in either index.
The VQI frailty index is more efficacious in amputation and mortality risk stratification than the mFI. The VQI may be used as a screening tool to identify patients who are at high risk for amputation and death. It is a tool that can assist with informed decision-making in patients with CLI.