Majority of Patients Undergoing Major Leg Amputations for Chronic Limb-threatening Ischemia Don't Undergo Revascularization Prior to Amputation and Have Increased Mortality.

Abstract

Background: Many patients with Chronic Limb Threatening Ischemia (CLTI) undergo lower extremity amputations and recent data has shown that revascularization operations are not offered to many patients with CLTI, who may benefit from such operations. This study aims to evaluate the proportion of patients with CLTI who undergo major lower extremity amputation without prior revascularization attempts and to assess postoperative outcomes among all patients undergoing major lower extremity amputations, using data from a large national database.

Methods: The TriNetX database was queried for all peripheral arterial disease patients from 2000 to 2020 who underwent first-time major lower extremity amputation (at either below the knee level or above the knee level). This sample was divided into two cohorts: No History of Interventions before amputation (Group I) vs. History of single or multiple vascular Interventions before amputation (Group II). The primary outcome was mortality at one and three years postoperatively. Secondary outcomes included MI, PE, stroke, DVT, heart failure, dysrhythmias and major adverse cardiac event (MACE) assessed at 30-days and one year. Group II was further divided into subgroups based on the number of revascularization attempts: "0", "1-4", "5-8", and ">8". Univariate analysis was performed via t-test and Chi squared test. Multivariable logistic regression was performed to assess the association of revascularization history with mortality. Significance was set at p-value < 0.05.

Results: A total of 5,328 patients met inclusion criteria. Group I included 3,110 patients while Group II included 2,328 patients. Group I patients were more likely to be younger, non-white race, and have a history of hypertension, hyperlipidemia, heart failure, COPD, and CAD. Group I demonstrated increased mortality at both one (32% vs 28.1%; adj. p=0.005) and three years (45.6% vs 40.4%; adj. p<0.001) postoperatively. Furthermore, these patients experienced higher MACE (12.4% vs 10.4%; p=0.021) at the 30-day timepoint. Multivariable-adjusted analysis confirmed that history of revascularization was associated with a decreased risk of one-year mortality (AOR 0.82 [0.73, 0.94]; p=0.003) and three-year mortality (AOR 0.78 [0.70, 0.88]; p<0.001). Subgroup analysis demonstrated lower mortality risk with greater number of interventions (AORs of 0.81 (0.72, 0.92), 0.67 (0.53, 0.86) and 0.66 (0.42, 1.05)).

Conclusion: Patients who undergo revascularization attempts prior to major lower extremity amputation are less likely to experience mortality at one and three years postoperatively. These patients also received the best medical therapy more often, and the number of revascularizations before amputation correlated with the duration of limb preservation before ultimate amputation.