Prognostic value of the Society for Vascular Surgery Wound, Ischemia, and foot Infection (WIfI) classification in patients with no-option chronic limb-threatening ischemia

Abstract

ObjectiveThe Wound, Ischemia, and foot Infection (WIfI) classification was developed to assess amputation risk and hence to aid in clinical decision-making in patients with chronic limb-threatening ischemia (CLTI). WIfI has been validated in multiple CLTI cohorts worldwide. In this study, we examined the relationship between WIfI stage and clinical outcomes in a well-defined subpopulation of CLTI patients considered not eligible for conventional revascularization. The aim of this study was to assess the prognostic value of the WIfI classification for clinical outcomes in a “no-option” CLTI population. MethodsThe Rejuvenating Endothelial Progenitor Cells via Transcutaneous Intra-arterial Supplementation (JUVENTAS) trial was a single-center, double-blinded, randomized placebo-controlled trial studying the effects of autologous bone marrow mononuclear cells in no-option CLTI patients (N = 160). We conducted a retrospective analysis incorporating baseline and follow-up data from the JUVENTAS trial. All wounds were photographed and described at the start and end of the trial to allow WIfI staging. Two independent researchers retrospectively classified all limbs according to the WIfI scheme, which was then related to prospectively collected trial data. Outcomes including wound healing, clinical improvement, minor and major amputation rate, amputation-free survival, and mortality were assessed using Kaplan-Meier analyses. ResultsOf the 160 patients, 150 could be included in this study. Most patients had been classified as Rutherford stage 4 (34%) and stage 5 (61%), with corresponding WIfI stage 2 (33%), stage 3 (21%), or stage 4 (35%). Diabetes, impaired renal function, and ankle-brachial index were independently associated with WIfI stage. On univariate analysis, WIfI stage was strongly associated with wound healing (P = .001), improvement of Rutherford stage (P = .009), amputation rate (P < .001), and long-term mortality (median follow-up, 21.1 months; P = .025). Of note, WIfI stage 2 patients had a worse 6-month major amputation rate compared with stage 3. Of the seven amputated stage 2 patients, six were in WIfI category W0-I3-fI0 and scored a maximum grade 3 on ischemia. Reclassification of ischemic rest pain (W0-I3-fI0) to stage 3 improved and reordered the discrimination of outcomes by WIfI stage in this cohort. ConclusionsThis is the first study to demonstrate that WIfI classification is associated with important clinical outcomes in a no-option CLTI population. Our data suggest that limb prognosis is poor in patients with classic ischemic rest pain, without wounds or infection (W0-I3-fI0), when they lack revascularization options. Further studies are needed to determine whether reassignment of this population from WIfI stage 2 to WIfI stage 3 may be appropriate to reflect amputation risk in the absence of successful revascularization for patients suffering from ischemic rest pain in general.