Novel Oral Anticoagulants in Patients with Continuous Flow Left Ventricular Assist Devices

Abstract

Purpose The gold standard for anticoagulation in patients with continuous flow left ventricular assist device (CF-LVADs) is warfarin. However, many patients fail warfarin therapy due to thromboembolic and bleeding events. Warfarin requires regular monitoring and dosage adjustments, and is associated with significant patient time outside recommended therapeutic INR range. Novel oral anticoagulation (NOAC) has been shown to be non-inferior compared to warfarin in stroke prevention with less intracranial hemorrhage in patients with atrial fibrillation. In this study, we sought to evaluate the safety and efficacy of NOACs in patients with CF-LVADs after failed warfarin therapy. Methods Patients who underwent CF-LVAD insertion between 2008 and 2018 were identified in a single-center database. 7 patients with either HeartMate II or HeartWare were switched from warfarin to a NOAC, either apixaban or rivaroxaban, were included. Occurrence of stroke, non-CNS embolism, pump thrombosis, and major GI bleeding or intracranial hemorrhage on warfarin and NOAC were evaluated. Results 5 of 7 patients were male, with an average BMI of 30. Common comorbidities were hypertension (100%), diabetes mellitus (57%) and ischemic cardiomyopathy (57%). There were a total of 3968 patient days on warfarin and 1459 patient days on a NOAC. Patients on warfarin therapy spent an average time of 30% within a therapeutic INR range. The rates of complications under warfarin versus NOAC therapy were: strokes 0.019 vs. 0 /patient-year, non-CNS embolism 0.019 vs. 0 /patient-year, pump thrombosis 0.01 vs. 0 /patient-year, major GI bleeding 0.02 vs. 0.07 /patient-year, and intracranial hemorrhage 0.019 vs. 0 /patient-year.(Table 1). Conclusion Increased complication rates and poor time in therapeutic INR range were present in patients receiving warfarin therapy after CF-LVAD insertion. NOAC therapy with apixaban or rivaroxaban may be a viable alternative. However, large prospective studies are necessary to confirm these results.