1: Anticoagulation With Bivalirudin vs Heparin Post Left Ventricular Assist Device Implantation

Introduction: Left ventricular assist devices (LVADs) require lifelong anticoagulation to prevent thrombosis and pump-related complications. Device approval studies utilized heparin as the parenteral anticoagulant in the immediate postoperative period and evidence is therefore limited for the use of bivalirudin. The objective of this study was to determine if a difference in bleed risk exists comparing bivalirudin vs heparin immediately following LVAD implantation. Methods: This single center, retrospective study included adult patients who received bivalirudin or heparin within 5 days of LVAD implantation at Nebraska Medicine between July 1, 2016 and April 30, 2025. Exclusions were incarceration, pregnancy, implantation of a total artificial heart, and use of Extracorporeal Membrane Oxygenation (ECMO), Impella, or balloon pump post-op. The primary outcome was a composite of major and minor bleeding events within 7 days of anticoagulation start or 24 hours after discontinuation, whichever was sooner. Secondary outcomes were thromboembolic events, time in therapeutic range (TTR), and post-op ICU/hospital length of stay (LOS). Fisher’s exact test was used for categorical variables and independent samples t-test or Wilcoxon rank sum test for continuous. Characteristics and results are presented as mean/SD or median/IQR and counts/percentages. A p-value < 0.05 was considered statistically significant. Results: Analysis included 267 patients (163 bivalirudin vs 104 heparin) after 16 were excluded. Patients were male (74.9%), aged 56.3 (±12.7) years, with INTERMACs score 2 (31.6%), NYHA classification IV (83.3%), and BMI 30 (±7.1). HeartMate 3 device was most common (86.9%), indicated for destination therapy (71.9%) or bridge to transplant (22.8%). Bleed incidence was similar for bivalirudin (23.3%) and heparin (26.0%) groups (p=0.662). The majority of bleeding events for bivalirudin (86.0%) and heparin (86.7%) were minor, and there was no difference in thrombotic events (1.2% vs 2.9%), post-op ICU LOS (15.0 vs 12.1 days), or post-op hospital LOS (28.4 vs 24.1 day). Heparin resulted in a higher TTR (54%) vs bivalirudin (32%) (p < 0.001). Conclusions: Similar rates of bleeding and thromboembolic events were observed comparing bivalirudin and heparin in the immediate postoperative period following LVAD implantation.