SVS WIfI wound classification system for CLTI risk stratification

in Lower Extremity Arterial Disease

Applied

Type

Addition

Confidence

90%

Created

Mar 19, 2026

Evidence

1 source

Rationale

The 2025 ACC Scientific Statement on PAD in diabetes provides high-level support for the WIfI system, specifically highlighting its role as the preferred tool for this high-risk population. This addition strengthens the section by providing contemporary guideline-based validation. Abbreviations (SVS, ACC, TcPO2) were expanded per instructions.

Content Changes

The SVSSociety for Vascular Surgery (SVS) Wound, Ischemia, and foot Infection (WIfI) classification system stratifies chronic limb-threatening ischemia (CLTI) risk by combining three domains: **Wound** (W0–3), **Ischemia** (I0–3), and **foot Infection** (fI0–3) to generate an overall limb threat stage (Stages 1–4). Higher WIfI stages correlate with increased 1-year amputation risk and greater potential benefit from revascularization. Recent scientific statements from the American College of Cardiology (ACC) reinforce WIfI as the preferred classification system for risk stratification and clinical decision-making in adults with diabetes and CLTI [@acc2025-e]. Objective ischemia thresholds include toe pressure (I0: ≥40 mmHg; I1: 30–39 mmHg; I2: <30 mmHg; I3: <30 mmHg with rest pain) and TcPO₂transcutaneous (I0:oxygen tension (TcPO₂; I0: ≥40 mmHg; I1: 30–39 mmHg; I2: <30 mmHg; I3: <30 mmHg with rest pain). WIfI should be documented at baseline and reassessed after revascularization to evaluate treatment response [@mills2014, @conte2019].

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**WIfI Limb Threat Stage Matrix**

| **WIfI Stage** | **1-Year Amputation Risk** | **Revascularization Benefit** |
| --- | --- | --- |
| 1 (Very low) | <5% | Low |
| 2 (Low) | 5–10% | Moderate |
| 3 (Moderate) | 10–20% | High |
| 4 (High) | >20% | Very high |