Bivalirudin versus Heparin for Anticoagulation in Children on Paracorporeal Pulsatile Ventricular Assist Device Support at a Single Tertiary Pediatric Heart Center

Background: With the increasing use of cardiac support devices in children, complications and outcomes on ventricular assist device (VAD) support require systematic evaluation. Cerebrovascular events remain a relevant burden due to their high impact on morbidity and mortality. Adequate anticoagulation is of major importance to prevent bleeding and thrombotic events in these patients. Bivalirudin, a direct thrombin inhibitor, emerges as a promising alternative to unfractionated heparin (UFH) for anticoagulation on VAD support due to its predictable anticoagulant effect, short half-life, and lower risk of heparin-induced thrombocytopenia.

Methods: We conducted a retrospective chart review of children aged 0–17 years on paracorporeal pulsatile (PP) and pneumatically driven VAD support at the Medical University of Vienna from April 2011 to March 2023. Patients received anticoagulation therapy with UFH or low-molecular weight heparin (LMWH), and since 2021, with bivalirudin. The study aimed to assess hemocompatibility-related adverse events (HRAEs) stratified by the two different anticoagulation strategies. Event rates were calculated as mean of events per 100 patient VAD days, and compared using an unpaired t-test.

Results: Twenty-nine patients on VAD support were included, 19 patients were primarily treated with UFH or LMWH, and 10 patients with bivalirudin. Age groups comprised 52% under year, 27% 1–5 years, 14% 6–10 years, and 7% 11–17 years. Main indications for device implantation were cardiomyopathy (52%), congenital heart disease (28%), and myocarditis (17%). Device types were mainly left (38%) and biventricular (34.5%) VAD systems and the prevailing device strategy was bridging to transplantation (83%). The median duration of VAD support was 58 days (IQ range: 26–135 days). The total rate of HRAEs was 4.3 per 100 VAD days in the heparin group and 1.6 per 100 VAD days in the bivalirudin group (p = 0.003). Most HRAEs were pump thromboses with numerically higher rates in the heparin group (2.5 vs. 1.2 per 100 VAD days, p = 0.11). The rate of bleeding events was slightly higher (1.0 vs. 0.2 per 100 VAD days, p = 0.066) and the rate of arterial thromboembolism events slightly lower (0.1 vs. 0.2 per 100 VAD days, p = 0.63) in the heparin group. Events of stroke (hemorrhagic or ischemic) and seizures were only observed in patients treated with heparin (0.4 per 100 VAD days, p = 0.038; 0.3 per 100 VAD days, p = 0.10; respectively).

Conclusion: The use of bivalirudin for anticoagulation of children on PP and pneumatically driven VAD support was associated with overall lower rates of HRAEs compared with UFH or LMWH.

Publikationsverlauf

Artikel online veröffentlicht:
13. Februar 2024