Predictors of Amputation-free Survival after Endovascular Intervention for Chronic Limb-Threatening Ischemia in the Modern era

Abstract

Background: Chronic limb-threatening (CLTI) is associated with 25% limb loss and 25% mortality at 1-year. Its lethality increases to 45% in patients subjected to a major amputation. Percutaneous peripheral intervention (PPI) constitutes an attractive and less morbid treatment option for patients with CLTI. The purpose of this study was to assess amputation-free survival (AFS) in a contemporary cohort treated with endovascular recanalization and assess its predictors.

Methods: Patients with CLTI undergoing endovascular revascularization at a single regional hospital between 2015-2019 were reviewed. Baseline demographic characteristics, Wound, Ischemia, and foot Infection (WIfI) stage, technical details, and clinical outcomes were tabulated. The primary endpoint was AFS; a P-value < 0.05 was used for univariate screening and inclusion in a multivariable model.

Results: A total of 137 limbs in 111 patients were studied. Comorbidities were prevalent and included diabetes (65%), congestive heart failure (21%), and dialysis dependence (18%). The majority of revascularized limbs presented with advanced wounds (66% WIfI stages 3-4; 47% Rutherford category 6). Presenting WIfI stages were similar across races (P = 0.26). Peripheral interventions most commonly targeted femoropopliteal disease (69%), although 26% were multilevel. Percutaneous atherectomy, stenting, and paclitaxel-coated or eluting devices were utilized in 68%, 28%, and 15% of cases, respectively. After a median follow-up of 16 months (interquartile range IQR = 4-29 months), significant independent predictors of reduced AFS included nonWhite race (HR = 2.96 [1.42-6.17]; P = 0.004) and WIfI stage 4 wounds (HR = 2.23 [1.10-4.52]; P = 0.026). At one year following successful revascularization, only 59% ± 1% of patients were alive with their limb intact.

Conclusions: Despite considerable and consistent advances in urban health care delivery and the techniques of PPI, CLTI remains a morbid and deadly disease. Even in the endovascular era, nearly half of all patients presenting with CLTI will lose their limb and/or life within the first year. Unfortunately, late-stage presentation continues to be commonplace. Although endovascular intervention can reliably restore patency to affected arteries, this appears insufficient to restore most patients to health.