The Impact of Aspirin Dose on Hemocompatibility-Related Adverse Events during HeartMate 3 Support - An Analysis from the MOMENTUM 3 Trial

PURPOSE: Antiplatelet therapy with aspirin (ASA) is mandated with Left Ventricular Assist Devices (LVADs) on the presumption that this therapy modulates Hemocompatibility-related adverse events (HRAEs). The effect of aspirin (ASA) dosing, particularly during support with the HeartMate 3 (HM3) LVAD is unknown. METHODS: We conducted an exploratory analysis of HM3 supported patients in the MOMENTUM 3 clinical trial. HM3 patients were categorized into 2 groups based on daily ASA dose as Usual-dose (325 mg) or Low-dose (81 mg) with anticoagulation targeted to an INR 2.0-3.0. Exclusion criteria included patients not receiving either ASA 81mg or 325mg dose, those with HRAEs ≤7 days after LVAD implantation, or those receiving >1 antiplatelet agent. The composite primary endpoint was freedom from HRAEs, including non-surgical bleeding, pump thrombosis, stroke and peripheral arterial thromboembolic events at 2 years. RESULTS: Overall, 321 HM3 patients (Usual-dose n=141; Low-dose n=180) were included. Patients in the Usual-dose group were younger (57±13 vs. 60±12 years, p=0.035) and less often implanted as destination therapy (55% vs. 67%, p=0.029) than those receiving Low-dose. INR at the time of HRAEs was clinically similar between Usual- and Low-dose groups (2.20 [1.66, 3.20] vs. 2.0 [1.50, 2.60], p=0.054 respectively). At 2 years, a similar proportion of patients in the Usual- and Low-dose (43.5% vs 45.3%, p=0.94, Figure 1) groups survived free from HRAEs. There were no differences in survival free from component hemorrhagic (Usual-dose: 54.4% vs Low-dose: 51.7%, p=0.42) and thrombotic (Usual-dose: 76.8% vs Low-dose: 75.7%, p=0.92) events. CONCLUSION: At 2-years after HM 3 LVAD implant, no difference in HRAEs between Usual- and Low-dose ASA was shown in the MOMENTUM 3 clinical trial. These findings suggest similar efficacy and safety of these two distinct aspirin dose ranges and call into question any meaningful therapeutic effect of this agent in HM 3 treated patients.