Editor's Choice - The Prognostic Value of the WIfI Classification in Patients with Chronic Limb Threatening Ischaemia: A Systematic Review and Meta-Analysis

Objectives: The Society for Vascular Surgery has proposed the Wound, Ischaemia, and foot Infection (WIfI) classification system as a prognostic tool for the one year amputation risk and the added value of revascularisation in patients with chronic limb threatening ischaemia (CLTI). This systematic review summarises the current evidence on the prognostic value of the WIfI classification system in clinical practice. Design: Systematic review and meta-analysis following the PRISMA guidelines. Materials: The Embase, MEDLINE, and Cochrane databases were searched up to June 2018. Methods: All studies using the WIfI classification for patients with CLTI were eligible. Outcomes of interest were major amputation, limb salvage, and amputation free survival in relation to WIfI clinical stage. The methodological quality of studies was appraised with the Quality in Prognosis Studies (QUIPS) tool. If possible, data were pooled and analysed using a random effects model. Study selection, quality assessment, and data extraction were carried out by two authors independently. Results: The search yielded 12 studies comprising 2669 patients, most of whom underwent endovascular or open revascularisation. Overall study quality was moderate. All but one were retrospective studies, including a variety of subpopulations of patients with CLTI, such as only haemodialysis dependent, diabetic or non-diabetic patients. The WIfI classification was derived from chart data or prospectively maintained databases, both documented before the WIfI classification was published. Estimated one year major amputation rates from four studies comprising 569 patients were 0%, 8% (95% CI 3-21%), 11% (95% CI 6-18%) and 38% (95% CI 21-58%), for WIfI stages I-IV, respectively. Conclusions: The likelihood of an amputation after one year in patients with CLTI increases with higher WIfI stages, which is important prognostic information. Prospective evaluations are needed to determine its role in clinical practice.