VESS06 - High-intensity Statin Therapy Reduces Risk of Amputation and Reintervention Among Patients Undergoing Lower Extremity Bypass for Chronic Limb Threatening Ischemia

Objectives: Statins are considered standard-of-care medical therapy for patients undergoing lower extremity bypass (LEB) procedures for chronic limb threatening ischemia (CLTI). However, it is unclear whether maintaining patients on higher-intensity statin medications following LEB improves limb salvage outcomes. This study was designed to evaluate the association between the intensity of statin therapy on risk of amputation and reintervention following LEB for patients with CLTI.

Methods: We used the nationwide Truven MarketScan database to identify adult patients (18-99 years old) who underwent a LEB for CLTI between 2008 to 2017. Patients were excluded if their insurance plan did not cover drug reimbursement, or if they had undergone an amputation before the time of their bypass. Using pharmacy claims and national drug codes to define statin intensity, patients were stratified into three groups: high-intensity, low-intensity, and no statin therapy. The association between intensity of statin therapy and need for reintervention and/or amputation after LEB was analyzed using Kaplan Meier curves and risk-adjusted Cox proportional hazard models.

Results: A total of 25,907 patients underwent LEB for CLTI, of which 4,695 (18.1%) were maintained on high-dose statins, 5,981 (23.1%) were on low-dose statins, and 15,231 (58.8%) had limited or no pharmacy claims for statin therapy after surgery. Patients on high-intensity statins were on average younger, and more likely to be male with comorbid disease (diabetes, hypertension, hyperlipidemia, obesity, renal insufficiency, ischemic heart disease, cerebrovascular disease, and tobacco abuse) than patients on low-intensity statins or no-statin therapy (P < 0.001 for all comparisons). Following LEB, 6,642 (25.6%) patients required a reintervention, and 2,550 (9.8%) went on to have a major amputation during follow-up. Patients maintained on high-intensity statins after LEB had a significantly lower likelihood of requiring a reintervention (HR:0.48; 95% CI:0.45-0.51; P< 0.001) or amputation (HR: 0.27; 95%CI:0.24-0.30) as compared to patients not on statin therapy (Figure 1 and 2). Further, there was a dose-dependent effect for these outcomes relative to patients on low-dose statin therapy, and it was independent of whether an autologous vein graft was used for the LEB. Finally, among patients who underwent a reintervention, high-dose statin therapy also significantly reduced the hazard ratio for subsequent amputation (HR:0.21; 95%CI:0.18-0.25; P< 0.001).

Conclusions: Patients with CLTI maintained on high-intensity statin therapy following LEB had a significantly lower risk of requiring subsequent reintervention and amputation. These results suggest that every effort should be made to initiate and/or intensify statin therapy in these high-risk patients following revascularization.