(IP135) The Incremental Risk of Major Amputation with Reinterventions in Patients with Peripheral Arterial Disease

Objectives: Peripheral arterial disease (PAD) necessitates multiple lower extremity revascularizations (LER) over time which impact healthcare costs and quality of life, especially for patients with chronic limb threatening ischemia (CLTI). This study compares reinterventions in patients treated with open and endovascular infrainguinal LER, focusing on the frequency of reinterventions and their impact on amputation.

Methods: Infrainguinal procedures from the Infrainguinal Bypass and Peripheral Vascular Intervention (PVI) modules of the Vascular Quality Initiative (VQI) from 2016-2024 were analyzed to identify each patients’ index LER. Bilateral procedures were excluded. Patients whose index LER indicated prior LERs, was a hybrid procedure, or was performed for acute limb ischemia were excluded. Patient characteristics were compared between index LER strategy, lower extremity bypass (LEB) and PVI. Frequency of reintervention was calculated through tracking and quantifying reinterventions over time using unique patient IDs across modules. A Kaplan Meier (KM) curve of the frequency of reinterventions and associated risk of amputation was derived.

Results: A total of 124,100 patients were analyzed, 15.7% of which were treated with index LEB. Patients treated with initial LEB were more likely to be younger, white and male compared to those treated with initial PVI (Table I). Initial LEB patients had significantly lower rates of most comorbidities and were more likely to be treated electively for CLTI. Initial PVI patients had a significantly higher mean number of ipsilateral reinterventions (0.27(0.66) vs 0.18(0.51), P< 0.001). Adjusting for time showed index PVI patients experienced a greater frequency of ipsilateral reinterventions (Table I). Negative binomial regression revealed index PVI (IRR=1.57[1.51-1.64]), female sex (IRR=1.15[1.12-1.19]), African American race (IRR=1.06[1.02-1.09]), diabetes (IRR=1.05[1.02-1.08]) and CLTI (IRR=1.26[1.22-1.30]) were associated with a higher number of ipsilateral reinterventions. KM analysis of major amputation showed no significant difference in amputation risk based on index LER strategy. However, a significant stepwise increase in major amputation risk was observed from 7.9% without reintervention to 41.7% after 3 or more reinterventions at 1.5 years after the initial procedure (Fig 1). Regression analysis shows that undergoing three or more reinterventions is associated with the highest hazard ratio of major amputation (HR=4.02[3.50-4.61]).

Conclusions: Patients undergoing index infrainguinal PVI experience a greater frequency of reinterventions compared to those treated with LEB, with index LER strategy being independently associated with more reinterventions. Although index LER strategy does not seem to directly influence amputation risk, the risk of major amputation increases significantly with the number of reinterventions.