Predictors of major adverse lower limb events in patients with tissue loss secondary to critical limb-threatening ischemia

Background: Chronic limb -threatening ischemia (CLTI) is the end -stage of peripheral arterial disease (PAD) posing a high risk for limb loss and mortality. This study aims to evaluate and list possible predictors of major adverse limb events (MALEs) in CLTI patients with tissue loss. Methods: This retrospective study included all Rutherford -Becker stage 5 or 6 patients who required foot debridement and revascularization in our department from January 2016 to December 2018. The limbs were classified according to the TASC II, GLASS and WiFI grading systems. The primary composite outcome was MALEs at 2 years. The secondary outcomes included all -cause mortality, primary patency, freedom from reintervention, and major amputation. KaplanMeier estimates were used to determine the event rates, and Cox proportional hazards model with the index MALE as a time -dependent covariate was used to search for MALEs predictors. Results: Of 241 included patients, 19 underwent open surgeries (7.9 %) 207 had endovascular interventions (85.9 %) and 15 required a hybrid approach (6.2 %). On univariate analysis, patients who experienced MALEs (n = 111) more often required hemodialysis (25 vs 15; p = .02), presented with more complex lesions (TASC D on femoropopliteal (p = .05) or below the knee (BTK) arteries (p = .006) with increasing infra-inguinal GLASS Stage (p < .0001)), a history of index limb open (p = .009) or endovascular (p = .049) revascularization, an occluded tibial artery (p = .002 for the posterior tibial and p = .052 for the anterior tibial), or a "desert foot" (p = .02). The CRP level was also higher at admission (p = .001). Technical success of BTK revascularization significantly reduced MALEs (p < .0001) along with the number of patent BTK vessels (p = .0007). Independent predictors of MALEs included hemodialysis (HR = 2.00; 95%CI: 1.14 to 3.39), pulsatile arterial pressure (HR = 1.01; 95%CI: 1.00 to 1.03) and the infrainguinal GLASS Stage (HR = 2.50; 95%CI: 1.17 to 5.82). We could not correlate our results with the WiFI scores for amputation risk and revascularization benefit.<br /> Conclusion: For patients with CLTI at the stage of trophic disorders, with or without a history of index limb revascularization, the GLASS successfully predicted MALEs. Hemodialysis and high pulsatile arterial pressure increased the risk of MALEs. The WiFI score did not demonstrate its interest in this subgroup of patients.