Thrombus formation in a HeartMate II

A HeartMate II was implanted as a bridge to transplant. The patient was transfused fresh-frozen plasma for gross hematuria 5 months later. He developed heart failure and evaluation revealed left ventricular assist device (LVAD) dysfunction. He underwent LVAD exchange (Video 1). A thrombus was noted in the inlet bearing ball and bearing cup (Fig. 1 ). Thrombus found in the inlet bearing ball and bearing cup upon dismantle of the HeartMate II LVAD. Baseline LVAD settings were speed of 10,000 rpm, pulsatility index of 5.7, power consumption of 7.6 W, and flow of 6.7 l/min. At the time of his readmission, echocardiogram demonstrated a distended left ventricle, elevated pulmonary artery pressures, and an aortic valve opening with each cardiac cycle. Although he clinically appeared to have inflow obstruction, his inflow cannula was well positioned had low velocity flow. LVAD settings were increased to 10,800 rpm; pulsatility index remained at 5.5, power consumption was 7.8 W, and flow was 4.8 l/min. Since the thrombus was in the inlet bearing ball and cup, it did not lead to increased power consumption, as would be the case if the thrombus was in the impeller itself. Supplementary data associated with this article can be found, in the online version, at doi:10.1016/j.ejcts.2010.06.015.