Antiplatelet Therapy and Adverse Hematologic Events During Heart Mate II Support

Area of Science:

• Cardiology
• Biomedical Engineering
• Pharmacology

Background:

• Hematologic adverse events are frequent complications in patients with continuous flow left ventricular assist devices (LVADs).
• The precise relationship between antiplatelet therapy, specifically aspirin (ASA) dosing, and these adverse events remains unclear.

Purpose of the Study:

• To investigate the impact of different aspirin (ASA) dosages, in conjunction with warfarin, on hemorrhagic and thrombotic outcomes in patients with Heart Mate II LVADs.
• To determine if higher ASA doses are associated with an increased risk of bleeding or a reduction in thrombotic events.

Main Methods:

• A single-center retrospective review of Heart Mate II LVAD patients from June 2006 to November 2014.
• Patients were stratified into three groups based on ASA dosage and warfarin management: ASA 81 mg + dipyridamole, ASA 81 mg alone, and ASA 325 mg.
• Hemorrhagic and thrombotic events were assessed within 365 days post-implantation, with survival analysis using Kaplan-Meier curves and Cox proportional hazard ratios.

Main Results:

• The group receiving high-dose aspirin (ASA 325 mg) experienced significantly higher rates of hemorrhagic events (54%) compared to those on ASA 81 mg + dipyridamole (26%) and ASA 81 mg alone (22%) (P = 0.004).
• Patients on ASA 325 mg had a significantly increased adjusted hazard ratio for bleeding events (HR 2.9 vs. ASA 81 mg + dipyridamole, P = 0.02; HR 3.4 vs. ASA 81 mg, P = 0.02).
• No significant differences in the rates of thrombotic events were observed across the different aspirin dosing groups.

Conclusions:

• High-dose aspirin (325 mg daily) in Heart Mate II patients concurrently treated with warfarin is associated with a substantially increased risk of bleeding.
• The increased bleeding hazard with high-dose aspirin does not confer a benefit in reducing thrombotic events in this patient population.
• Optimal antiplatelet strategies, including aspirin dosing, require careful consideration to mitigate bleeding risks while maintaining efficacy in LVAD patients.