Anticoagulation with coumarin derivatives in left ventricular assist device (LVAD) patients is essential to prevent hemocompatibility related adverse events (HRAEs), but is challenging due to inter- and intra-individual variability of dose response and small therapeutic window. The aim of this study was to describe differences in quality of anticoagulation, HRAEs, and outcomes in users of phenprocoumon and warfarin.
This retrospective, multicenter study included 179 patients (Age: 57.4±11.8 yrs, female: 23.5%, BMI: 28.6±5.9kg/m2, HM3/HVAD: 50.8%/49.2%) implanted at the Medical University of Vienna (n=102 phenprocoumon) and University of Chicago (n=77 warfarin), between 2014 and 2018. Primary outcome was INR TTR during one-year after first follow-up visit (FFUV), secondary outcomes included all-cause mortality, freedom from- and the evaluation of independent risk factors for the occurrence of HRAEs.
During follow-up, phenprocoumon vs. warfarin users had a significantly higher TTR (64.9±16.1% vs. 37.7±21.8%, p<0.001). One-year survival (86.3% vs. 89.6%, p=0.65) and freedom from HRAE (59.8% vs. 54.5%, p=0.54) were comparable to both drugs/centers, but first HRAEs occurred earlier with warfarin (126 vs. 46 days post FFUV, p=0.002). In a multivariate cox proportional hazard model, female gender [hazard ratio (HR) 2.15, 95% CI 1.12-4.11; p=0.021], no beta blockers at FFUV (HR 2.16, 95% CI 1.03-4.52; p=0.042), GI bleeding pre-implant (HR 3.41, 95% CI 1.32-9.45; p=0.018) and time between INR tests (HR 0.85, 95% CI 0.74-0.99; p=0.03) were associated with a significantly higher risk of HRAEs, but drug/device type were not independent risk factors.
Despite similar working mechanism of phenprocoumon and warfarin, differences in pharmacokinetics may affect anticoagulation quality. Gender, time between INR tests, absence of beta blockers and GI bleeding pre-implant are independent risk factors for HRAEs during LVAD support.
© 2021 Published by Elsevier Inc.