HeartMate II thrombosis treated without explantation in the waiting period for heart transplantation: a case report

BACKGROUND: The HeartMate II (HMII) is a high speed, axial flow, rotary blood pump that restores systemic flow by draining blood from the left ventricular (LV) apex and ejecting into the aortic root. This LV assist device was previously used in patients with medically refractory advanced-stage heart failure, for both destination therapy and bridge to transplantation until the introduction of HeartMate III. CASE SUMMARY: We report herein a case of a 25-year-old patient with Interagency Registry for Mechanical Assisted circulatory 3 profile implanted with HMII device for an end-stage dilated cardiomyopathy, who experienced a pump thrombosis despite a well-conducted anticoagulant protocol. A thrombophilia with heterozygous mutation of factor II and V was diagnosed at that time. We chose to stop the device without explantation until heart transplantation. DISCUSSION: Pump thrombosis with HMII is associated with a prohibitive risk of morbidity and mortality. Pump thrombosis is suspected when haemolysis or congestive heart failure occurs, also in cases of overconsumption of pump power (>10 W). Pump thrombosis treatment is challenging in the case of clotting factors mutation. Pump exchange could be ineffective, exposing the patient to the recurrence of thrombo-embolic events. Intravenous thrombolysis may be used for patients not candidates for redo procedures but could be unsuccessful and expose patients to high bleeding risk. Heart transplantation remains a reliable option. In our case, pump explantation was considered too hazardous by the heart team due to a prohibitive risk of redo surgery. Then, we decided to turn off the HMII pump after the introduction of continuous intravenous dobutamine support. The haemodynamic stability allowed us to wait for heart transplantation in favourable conditions.