Hemocompatibility-Related Adverse Events Associated With or Without Low Molecular Weight Heparin Bridging in Outpatients With a HeartMate 3 Left Ventricular Assist Device.

Background: Prior studies of anticoagulation bridging during periods of low International Normalized Ratio (INR) in outpatients with a durable, continuous flow left ventricular assist device (CF-LVAD) have shown a variable impact on thrombotic and bleeding events. These studies include predominantly older devices such as the HeartMate 2 (HM2) and HeartWare HVAD, which are known to experience more overall thrombotic events than the HeartMate 3 (HM3) device. The majority of these patients also received concomitant aspirin.

Methods: The primary objective of this study was to compare hemocompatibility-related adverse events (HRAEs) occurring while bridging subtherapeutic (≤ 1.7) INRs with therapeutic low-molecular weight heparin (LMWH) versus not bridging in outpatients with an HM3 CF-LVAD, many of whom were not receiving concomitant aspirin.

Results: Of the 79 patients eligible for inclusion in this study, 64 were not bridged and 15 were bridged at least once during the study period. In the non-bridged group, there were a total of 12 HRAEs of 997 bridging opportunities (BOs) (1.20%) versus 0 of 39 BOs in the bridged group. Of the 12 HRAEs in the non-bridged group, 10 were bleeding events; the 2 thrombotic events were minor venous thromboembolisms.

Conclusion: Omission of LMWH bridging in HM3 CF-LVAD patients with a subtherapeutic INR and low rates of background aspirin use did not result in a statistically significant or clinically relevant increase in the rate of HRAEs.