FRAILTY STATUS BEATS WIFI SCORE AS MORTALITY PREDICTOR IN ALL-COMER CLTI STUDY

A study presented during Thursday’s Plenary Session 3 concluded that the Wound, Ischemia, and Foot Infection (WIfI) stage is predictive of major amputation at one-year follow-up in patients with chronic limb-threatening ischemia (CLTI), while frailty status is a better predictor of mortality. The researchers also found that, at baseline, WIfI classification is associated with both frailty and disability but not quality of life (QoL).

By Jocelyn Hudson

SUBMITTING AND PRESENTING author John Houghton, MD, a National Institute for Health and Care Research (NIHR) academic clinical lecturer at the University of Leicester in Leicester, England, opened his talk by noting that the WIfI classification system has been widely adopted in CLTI management; however validation has predominantly been among patients undergoing revascularization. The present study, therefore, aimed to investigate the association of WIfI stage with baseline frailty, disability, and QoL, in addition to one-year major amputation and survival, in all-comers with CLTI.

Outlining the study methods, Houghton noted that the research team performed a single-center prospective cohort study of patients aged ≥18 with CLTI, who were enrolled in the study between May 2019 and March 2022. He noted that frailty, disability and QoL assessments were performed at baseline, with an interim analysis of one- year outcomes performed in January 2023.

The presenter continued that amputation incidence was calculated for WIfI stages, and individual WIfI score combinations with ≥5 patients, and presented as percentages with 95% confidence intervals (CI).

Houghton, who presented this study on behalf of senior author Rob Sayers, professor of vascular surgery at the University of Leicester, and colleagues, detailed that a total of 432 patients were included in the research. He shared that 52 patients (12%) classified as WIfI stage 1, 112 (25.7%) stage 2, 107 (24.8%) stage 3, and 93 (21.5%) stage 4. There were 69 patients (16%) who had incomplete WIfI scores.

Sharing key results with the VAM audience, Houghton reported that increasing WIfI stage was associated with increasing prevalence and severity of frailty (p=0.003), and greater disability (p<0.001). He added that QoL scores, however, were similar for each WIfI stage.

In addition, the presenter revealed that major amputation incidence at one-year follow-up was 2% (95% CI, 0–11) for WIfI stage 1, 7% (95% CI, 4–14) for stage 2, 8% (95% CI, 4–15) for stage 3, 20% (95% CI, 13–30) for stage 4, and 16% (95% CI, 9–27) in those patients with incomplete WIfI scores. It was specified that amputation incidence for individual WIfI scores was largely consistent with stage classification.

Houghton further reported that increasing WIfI stage was independently associated with one-year major amputation (subdistribution hazard ratio [SHR], 1.99; 95% CI, 1.33–2.97, p=0.001), and was also associated with one-year mortality (HR, 1.31; 95% CI, 1.03–1.67; p=0.029). Frailty (clinical frailty score ≥5; HR, 2.18; 95% CI, 1.26–3.76; p=0.005) and non-operative management (HR, 4.42; 95% CI, 2.63–7.41; p<0.001), the presenter stated, were found to be the strongest predictors of mortality at one year.

“These results from the Leg ischemia management collaboration (LIMb) study provide further validation of the utility of the WIfI score in classifying patients with CLTI by risk of major amputation at oneyear,” Houghton told VS@VAM ahead of his presentation. “These data are particularly useful as all not all patients presenting with CLTI require, or are suitable for, revascularization but most of the published data on the WIfI score come from patients undergoing intervention. The LIMb patient cohort is a representative sample of CLTI patients and nearly 25% of patients included were initially managed conservatively. The finding that both frailty and disability were associated with increased WIfI stage highlights both the vulnerability of this patient population and the potential benefits of successful revascularisation, but the lack of association of WIfI score with quality of life is counter-intuitive and warrants further exploration.”