Thrombosis in Continuous Flow Left Ventricular Assist Devices: Our Clinical Experience With Medical and Surgical Management.

BACKGROUND: Continuous-flow left ventricular assist devices (CF-LVADs) such as the HeartMate II and HeartWare left ventricular assist device are important alternatives to heart transplantation. Thrombosis is a serious complication in both devices and we present our approach to treating thrombosis and analysis of predisposition factors.

METHODS: Our center's CF-LVADs database was retrospectively reviewed for pump thrombosis between January 2011 and January 2015. The patients were grouped for pump thrombosis (n = 13) and nonpump thrombosis (n = 85). Patients with pump thrombosis were further divided by device type (n = 5 HeartMate II and n = 8 HeartWare left ventricular assist device). Predisposition factors for pump thrombosis, our treatment approach, and patient outcomes were evaluated.

RESULTS: Pump thrombosis was diagnosed in 13 of 98 patients. The rate of pump thrombosis did not differ between the 37 HeartMate II and 61 HeartWare left ventricular assist device patients. High mean arterial blood pressure (P < .01) and noncompliance with the anticoagulation regimen (P = .04) were associated significantly with thrombosis. Twelve patients with stable hemodynamics were treated initially with intravenous tissue plasminogen activator and 1 patient who had end-organ damage underwent pump exchange. Two patients failed to respond to medical treatment and underwent pump exchange. Two patients with recurrent thrombosis were administered intracardiac tissue plasminogen activator. Five patients died after medical treatment and 4 deaths were due to cerebral hemorrhage.

CONCLUSIONS: Avoiding increased mean arterial blood pressures and ensuring optimal anticoagulation may help to decrease pump thrombosis. In patients with pump thrombosis, thrombolytic therapy is an alternative that is less invasive than pump exchange, but carries the risk of hemorrhage and thromboembolism.