Comparison of two individualized antithrombotic protocols in HeartWare HVAD recipients

We previously reported low rates of pump thrombosis and hemorrhagic stroke, but increased bleeding, under our original antithrombosis protocol (P1) in HeartWare recipients. We designed and implemented a revised protocol (P2) to reduce complexity and bleeding. Thrombelastography and PFA-100 guide antiplatelet titration. Goals for P2 were altered to decrease antiplatelet use and anticoagulation intensity. We compared the incidence and rates of gastrointestinal bleeding (GIB), embolic (eCVA) and hemorrhagic (hCVA) stroke, pump thrombosis (PT), and total bleeding (GIB+hCVA), total thrombosis (eCVA+PT), and total events between P1 and P2. Laboratory and medication data were assessed. Patients with and without hemocompatibility-related adverse events (HRAEs) were compared. The study included 123 patients (P1: 65; P2: 58). GIB rate decreased (P1: 0.66; P2 0.30 EPPY, P = .003). CVA rates and incidence were statistically similar, although hCVA incidence increased (P1: 3%; P2: 12%, P = .06). Incidence (P1: 3%; P2: 16%, P = .02) and rate (P1: 0.03; P2: 0.12 EPPY, P = .08) of PT increased. Incidence and rate of overall HRAEs and thrombotic events were similar, while bleeding rate decreased (P1: 0.69; P2: 0.40 EPPY, P = .02). Twelve-month medication burden decreased. Compared to non-HRAE patients, patients with bleeding HRAEs had more antiplatelet and pentoxifylline use, but less statin use; and lower PFAs. Patients with thrombotic HRAEs had less dual antiplatelet use, lower INRs, R-times, and PFA-ADP values. A revised antithrombotic protocol decreased GIB and overall hemorrhagic HRAE rate and medication burden. Unfortunately, PT increased. Non-HRAE and HRAE patients differed in anticoagulation and antiplatelet intensity. These differences will guide the revision of P2.