Early Improvement in Wound, Ischaemia, and foot Infection (WIfI) Ischaemia Grade Lowers Risk of Major Amputation following Revascularisation for Chronic Limb Threatening Ischaemia

ObjectiveThe Wound, Ischaemia, and foot Infection (WIfI) staging system for chronic limb threatening ischaemia (CLTI) predicts outcomes after revascularisation, but individual components of WIfI have not been evaluated. This study was designed to evaluate changes in WIfI ischaemia grade as a predictor of major amputation after open and endovascular revascularisation in the Best Endovascular versus Best Surgical Therapy in Patients with CLTI (BEST-CLI) trial.MethodsA secondary analysis was conducted of patients with CLTI randomised to surgical bypass or endovascular therapy as part of the BEST-CLI trial with available WIfI ischaemia scores at baseline and one month post-procedure. Risk adjusted Cox regression models were used to assess the effect of change in WIfI ischaemia grade on the rate of major amputation, while controlling for potential confounders.ResultsAmong 785 patients with CLTI who underwent revascularisation and were alive at one year, 629 (80.1%) achieved improvement in their WIfI ischaemia grade within 30 days after undergoing surgical and or endovascular interventions. Patients with improved ischaemia grade were younger and were more likely to smoke, have lower baseline ankle brachial indices, and have a worse overall WIfI stage at the time of revascularisation compared with patients with worsening or no improvement in limb perfusion (p < .050 for all comparisons). The major amputation incidence at one year was 14% and was increased among those with higher baseline WIfI stage (3/4 vs. 1/2) and with unchanged or worse WIfI ischaemia grade after revascularisation. Patients with improved WIfI ischaemia grade early after revascularisation had a statistically significantly lower likelihood of major amputation at one year (hazard ratio 0.27, 95% confidence interval 0.18 – 0.41; p < .001) after risk adjustment.ConclusionAchieving early improvement in limb perfusion based on WIfI ischaemia grade predicts major amputation following revascularisation independent of other risk factors. Changes in ischaemia grade after interventions should be closely monitored to determine the adequacy of revascularisation, risk of CLTI progression, and need for major amputation.