UC San Diego

Objectives

The beneficial effects of dual antiplatelet therapy (DAPT) compared to single antiplatelet therapy (SAPT) have been well established in coronary and carotid endovascular interventions; however, no consensus exists to the role of DAPT in lower extremity endovascular therapies (ET). We aimed to investigate the impact of postoperative DAPT following ET in patients presenting with chronic limb-threatening ischemia (CLTI) in the Vascular Quality Initiative-Medicare-Linked (Vascular Implant Surveillance and Interventional Outcomes Network [VISION]) database.

Methods

The study was a multicenter retrospective analysis of prospectively collected VQI-Medicare-Linked data. The VISION database was queried for all ETs performed for infrainguinal occlusive disease between 2011 and 2019. The patients were stratified by discharge antiplatelet regimen (DAPT vs. SAPT). SAPT patients received either aspirin or P2Y12 inhibitors whereas DAPT patients received both. The primary outcome was 1- and 5-year amputation-free survival (AFS). The secondary outcomes included 1- and 5-year overall survival, limb salvage (freedom from major amputation), and freedom from reintervention. Kaplan-Meier survival estimates and Cox regression were used for analysis.

Results

The study included two cohorts: SAPT (N=10,086, 41.7%) and DAPT (N=14,081, 58.3%). The patients in SAPT cohort were older than their DAPT counterparts and were more likely to have congestive heart failure and chronic kidney disease. While the patients in the DAPT cohort were more likely to have diabetes and coronary artery disease. In survival analyses, compared to SAPT, 1-year AFS in the DAPT cohort was 67.9% vs. 63.7% (P<.001) and 5- year AFS was 30.4% vs. 24.6% (P<.001). After adjusting for potential confounders, DAPT was associated with reduced hazards of major amputation or death at 1-year (adjusted hazard ratio [aHR]=0.82; 95% confidence interval [CI], 0.75-0.89; P<.001) and 5-year (aHR=0.91; 95% CI, 0.84-0.99; P=0.027). DAPT was also associated with lesser hazards of death (aHR=0.90; 95% CI, 0.81-0.99; P=0.048) and major amputation (aHR=0.86; 95% CI, 0.79-0.93; P<.001) at 1-year but not 5-year. Reintervention was not impacted by the antiplatelet therapy strategy. In our sub-analysis, we found superior five-year overall and amputation-free survivals in patients receiving DAPT compared to aspirin alone and also in patients receiving P2Y12 inhibitor alone compared to aspirin alone. However, the outcomes of DAPT vs. P2Y12 inhibitor alone were not significantly different.

Conclusions

In this large Medicare-linked national analysis, we found that DAPT is associated with improved AFS up to five years following ET in patients with CLTI compared to SAPT. However, there was no difference between DAPT and P2Y12 inhibitor alone. Additionally, P2Y12 inhibitor was associated with improved AFS up to five years compared to aspirin. Our findings support the use of DAPT or P2Y12 inhibitor following ETs performed in the lower extremity for CLTI; however, further prospective studies are required to confirm our findings.