Platelet inhibition with ticagrelor for left ventricular assist device thrombosis.

Abstract

Although considered standard therapy for Stage D heart failure since 2008, the continuous, axial flow HeartMate II (HMII) left ventricular assist device (LVAD) has recently been associated with unexpected rise in rates of pump thrombosis.1 With an incidence of 0.01 to 0.11 events per patient-year, LVAD thrombosis responds to intensification of antithrombotic therapy with unfractionated heparin (UFH), dual antiplatelet therapy with or without thrombolytics or glycoprotein IIb/IIIa inhibition in <50% of cases, and is associated with nearly 50% 6-month mortality.1 Therefore, surgical pump exchange or urgent transplantation remains the treatment of choice despite potential high risk and cost. Herein, we report the first successful experience using the potent P2Y12 ADP receptor inhibitor ticagrelor in addition to UFH and aspirin (acetylsalicylic acid [ASA]) to treat LVAD thrombosis and avoid pump exchange in 4 patients with confirmed or suspected HMII thrombosis. With institutional Instituitional Review Board approval, we reviewed medical records of 4 consecutive patients admitted to the cardiac intensive care unit at our institution with confirmed or suspected LVAD thrombosis. LVAD thrombosis was diagnosed in the presence of abrupt elevations of serum lactate dehydrogenase (LDH) to >900 mg/dL without (suspected LVAD thrombosis) or with (confirmed LVAD thrombosis) 1 of the following: (1) abnormal LVAD flows or power surges, (2) clinical symptoms of heart failure, or (3) supporting echocardiographic ramp study. We determined antiplatelet activity using VerifyNow P2Y12 assay, with values >230 P2Y12 reaction units (PRU) indicating nonresponder status. Patients were treated clinically using standard doses of medications based on clinical preference. ### Patient 1 A 28-year-old black man had HMII implanted as destination therapy for nonischemic cardiomyopathy before 7 days. Postsurgical course was complicated by slowly increasing LDH with peak of 980 U/L, requiring maintenance of UFH in addition to ASA 325 mg daily, dipyridamole, later switched to clopidogrel. Because LDH remained …