Prognostic Value of the Fibrosis-5 Index for Predicting 2-Year Adverse Outcomes in Patients With Peripheral Artery Disease Undergoing Endovascular Intervention.

BACKGROUND: To evaluate the prognostic role of the Fibrosis-5 (FIB-5) index in patients with peripheral artery disease (PAD) undergoing endovascular therapy.

METHODS: We screened 823 consecutive PAD patients and analyzed 537 after prespecified exclusions (mean follow-up 657 days). Patients were stratified into FIB-5 tertiles. FIB-5 incorporates routine laboratories-albumin, platelet count, alkaline phosphatase, and the aminotransferase/alanine aminotransferas ratio-per the Maeda formula; the FIB-4 index was also computed from baseline labs. Co-primary outcomes were major adverse cardiovascular events (MACE: cardiovascular death, nonfatal myocardial infarction, nonfatal stroke) and major adverse limb events (MALE: major amputation or target-limb revascularization) at 24 months. Prognostic performance was assessed with multivariable Cox models and receiver operating characteristic (ROC) analysis.

RESULTS: Higher FIB-5 values were associated with greater comorbidity burden and more complex lesions. After adjustment for conventional risk factors, FIB-5 independently predicted MACE (hazard ratio [HR] 1.62, 95% confidence interval [CI] 1.29-1.88) and MALE (HR 1.47, 95% CI 1.22-1.83). ROC analysis showed good discrimination for MACE (area under the curve [AUC] 0.895, 95% CI 0.831-0.921) and MALE (AUC 0.815, 95% CI 0.761-0.839), outperforming FIB-4.

CONCLUSION: FIB-5, derived entirely from routine laboratory tests, is prognostic for both MACE and MALE after endovascular treatment for PAD. Incorporation into preprocedural risk stratification may help identify higher-risk patients and guide secondary prevention and follow-up intensity. Confirmation in independent, multicenter PAD cohorts is warranted.