Abstract 9928: Risk Stratification for Amputation in Patients With Symptomatic Peripheral Artery Disease After Lower Extremity Revascularization: Insights From VOYAGER PAD

Introduction: Amputation is a severe consequence of peripheral artery disease (PAD), and systems for risk stratification have been developed. The performance of these systems in trials of PAD patients after successful lower extremity revascularization (LER) and receiving modern medical therapies has not been well described. Hypothesis: Risk of amputation is associated with the Rutherford Chronic Limb Ischemia class as well as the wound, ischemia, and foot infection (WIfI) grade in patients with PAD after LER. Methods: Patients in the VOYAGER PAD trial were assigned a Rutherford class at baseline and follow up. A WIfI score was assigned by 2 vascular specialists blinded to outcome and treatment allocation. Incidence of the composite of first major or minor amputation through 3 years were calculated by risk group. Results: Of 6,564 randomized, Rutherford was available in 6543 and WIfI in 6471. Due to the trial’s inclusion criteria, no Rutherford 6/WIfI high risk were included. Despite successful LER, there was a stepwise increase in the risk of amputation (p<.001) with increasing baseline Rutherford classification (Figure 1A) with incidence at 3 years of 22.4% in Rutherford 5. Risk was also associated with WIfI (Figure 1B); however, those classified as “very low” risk still a 15% incidence of amputation. When stratified by diabetes mellitus (DM), those with DM were at higher risk in all WIfI classes. Those with DM classified as "very low" risk had a higher incidence of amputation than patients without DM stratified as “moderate risk”. Conclusions: In a large clinical trial of patients with symptomatic PAD post successful LER, high incidences of amputation were observed despite contemporary medical therapies. In patients eligible for the study, Rutherford and WIfI both stratify risk; however, those with WIfI “very low” risk still had high incidences of amputation. Risk in those with DM was higher in each WIfI class suggesting that this could be considered in risk stratification.