A systematic review of the accuracy of prognostic tests and scoring systems for use in the Global Vascular Guidelines’ PLAN concept for the treatment of chronic limb threatening ischemia

Objective: The 2019 Global Vascular Guidelines recommend risk assessment for evidence based revascularization based on the acronym PLAN: Patient risk, Limb severity and ANatomical complexity of disease. This meta-analysis compares a multitude of prognostic tests within these categories. Methods: A systematic review and meta-analysis of tests that estimated 1-year major event (amputation-free survival and major adverse limb events) probability. Individual patient data were reconstructed from survival estimate curves. With presence or absence of major events, sensitivity, specificity, and area under receiver operating characteristics curves (AUC) were computed. Tests with an AUC ≥70%, or that correlated with revascularization feasibility were included. Practical application of tests was assessed to make a recommendation on PLAN implementation. Results: Ninety-six studies describing 77 unique predictive techniques were included, of which thirteen were sufficient. These 13 tests were divided in four Patient risk (5 studies), three Limb severity (3 studies), and six ANatomical complexity of disease (9 studies). Patient risk: Three tests were included: biochemical assessment of calprotectin and C-reactive protein, radiologic measurement of sarcopenia, and predictive score with the GermanVasc chronic limb-threatening ischemia (CLTI) score. These tests scored AUCs of 82.0%, 72.7%, and 71.8%, respectively, of which the GermanVasc CLTI score was deemed most applicable in clinical practice. Limb severity: The adjusted Wound Ischemia foot Infection score (WIfI) resulted as best predictive score (AUC, 78.8%), but due to the lack of external validation, the original WIfI score was deemed best applicable. ANatomical complexity of disease: No test surpassed 70% AUC for 1-year event estimation, and was correlated with feasibility of revascularization, the latter only being served by the Global Limb Anatomic Staging System. Conclusions: In evidence-based revascularization in patients with CLTI according to the PLAN concept, we recommend to use GermanVasc, WIfI, and the Global Limb Anatomic Staging System.