Can We Predict the Safety of Anticoagulation Therapy Cessation in HeartMate II Patients?

Objectives: In long-term left ventricular assist device (LVAD) therapy, recurrent bleeding events may justify cessation of anticoagulation therapy (AT). However, data about the safety and risks of AT cessation in LVAD patients are scarce.

Methods: Between 2010 and 2015, 128 patients received a HeartMate II (HMII). Following recurrent bleeding events, we ceased vitamin K antagonist (VKA) therapy in 13 patients (10%) (no-VKA group). To characterize the hemostatic profile, we performed von Willebrand factor (vWF), platelet function (PF), and other hemostatic tests in all HMII patients.

Results: The incidence of pump thrombosis (PT), ischemic stroke (IS), and bleeding events in this HMII population was 4.7, 6.2, and 36.7%, respectively. Median survival without VKA was 435 days. No significant changes could be detected with echocardiography in LV diameter (LV inner diameter in diastole pre- vs. post-AT cessation: 5.6 ± 1.1 vs. 5.5 ± 0.9, p = 0.272), or sphericity index (SI) (SI pre- vs. SI post-AT cessation: 0.65 ± 0.10 vs. 0.64 ± 0.10, p = 0.468), which could raise the suspicion of inflow cannula (IC) obstruction. No cases of PT and only one of IS occurred after AT discontinuation. All patients had impaired PF and acquired von Willebrand syndrome (AvWS). However, the vWF collagen-binding activity to antigen ratio before and after VKA cessation was significantly lower in the no-VKA group compared with the HMII population (0.60 ± 0.12 vs. 0.73 ± 0.14, p = 0.006). The thrombin–antithrombin III complex (TAT) value was significantly higher in the no-VKA group (p = 0.0005).

Conclusion: We experienced good results with AT cessation in specific HMII patients. The simultaneous onset of AvWS and high TAT values could explain at least in part the low thromboembolic rate in these HMII patients without VKA. Despite a reduced INR target (1.8–2.2), no increase in the thromboembolic rate was noted in our HMII patients. Further studies in a larger number of patients are needed to identify the hemostatic profile of patients who would benefit from anticoagulation cessation and those who would not.