Impact of Aspirin Dosing on Thrombotic Outcomes in Patients with the HVAD

Purpose Standard therapy with aspirin is recommended for patients after HVAD™ implantation. Bleeding in HVAD™ patients may lead to aspirin dose reductions or discontinuation to prevent future events. Previous studies in mixed cohorts of VAD patients have evaluated modified antiplatelet regimens with varied results regarding thrombotic outcomes. This study aims to report the impact of dose-reduced aspirin on thrombotic outcomes in HVAD™ patients. Methods This was a single-center retrospective evaluation of adult HVAD™ patients implanted from 7/1/2014 to 12/5/2018, maintained on therapeutic anticoagulation with warfarin. Outcomes were compared between two aspirin dosing groups: per-protocol aspirin (162 mg and 325 mg), and dose-reduced aspirin (0 mg and 81 mg). The primary endpoint was the composite incidence of ischemic stroke or pump thrombosis during the first year after implant. Secondary endpoints included ischemic stroke, pump thrombosis, gastrointestinal bleeding and hemorrhagic stroke. Results Seventy-six patients were analyzed (Table 1). No difference was observed between the two groups with respect to the composite primary endpoint of ischemic stroke or pump thrombosis (Figure 1). No statistically significant differences were observed in any of the secondary endpoints. Conclusion Numerically more events were observed in the dose-reduced aspirin group. In this cohort, dose reduction did not afford any benefit with regards to hemocompatability-related adverse events, indicating HVAD™ patients should be maintained on per-protocol aspirin dosing. More studies may add to the impactful nature of the results found in this investigation.