Bridging Therapy and Risk of Bleeding and Thrombosis in Continuous-Flow Left Ventricular Assist Device Patients: A Quasi-Experimental Study

Bridging with low-molecular-weight heparin (LMWH) is recommended in continuous-flow left ventricular assist device (CF-LVAD) patients during subtherapeutic international normalized ratios (INRs). We aimed to assess the risk of adverse events during bridging in patients implanted at Leiden University Medical Center between 2010 and 2024. Incidence rates and hazard ratios of major bleeding, thromboembolic events, neurologic complications, and death with 95% confidence intervals (95% CI) were estimated by time-dependent Cox regression. Using a regression discontinuity design, we mimicked a trial by comparing patients during LMWH treatment due to a subtherapeutic INR to patients during INRs just in target range and no LMWH, considering INRs ±0.1, ±0.2, ±0.3, ±0.4, and ±0.5 around the lower INR target range. Ninety-two patients were included, with a median age of 63 years, 73 (79%) were male and 43 (47%) had Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) 3. Major bleeding rates were increased during bridging in all analyses. Bridging had 3.7-fold (95% CI, 1.6-8.7) increased major bleeding risk compared with no bridging considering INRs ±0.1, and 2.8-fold (95% CI, 1.4-5.5) considering INRs ±0.5. Thromboembolic events were infrequent and not different between the two groups. Neurologic complications occurred more frequently during bridging. Moreover, the risk of mortality was 25.0-fold (95% CI, 3.6-173.1) increased during versus no bridging. Therefore, bridging should be considered with caution in CF-LVAD patients.