Validation of Wound, Ischemia, and Foot Infection Classification in Infrapopliteal Arterial Disease Undergoing...

The Wound, Ischemia, and Foot Infection (WIfI) classification system was proposed to improve risk stratification and prognostic prediction in chronic limb-threatening ischemia patients.

The aim of this prospective, multicenter observational study was to evaluate the prognostic value of the WIfI classification in patients with infrapopliteal arterial occlusive disease undergoing endovascular therapy.

Patients from 10 Chinese centers were enrolled. The primary outcome was 12-month freedom from major adverse events (MAE), which was a composite of major amputation, all-cause death, and clinically driven target limb reintervention. Secondary outcomes included amputation-free survival and the composite components of the primary outcome.

This study involved 944 patients (975 limbs). Cox regression analysis identified WIfI stage as an independent predictor of MAE (HR: 1.23; 95% CI: 1.06-1.43; P = 0.007). Additionally, WIfI stage was independently associated with combined major amputation or all-cause death (HR: 1.41; 95% CI: 1.18-1.69; P < 0.001) and with all-cause death alone (HR: 1.38; 95% CI: 1.12-1.70; P = 0.002). WIfI stage 4 carried a consistently higher risk for these 3 endpoints compared with stages 1 to 3. Although WIfI stage was independently linked to major amputation, pairwise comparisons did not show significant differences among stages. No independent association was observed between WIfI stage and clinically driven target lesion reintervention.

Although the WIfI classification system shows predictive ability for MAE, amputation-free survival, major amputation, and all-cause death, the prognostic differences are driven primarily by stage 4.