Worldwide experience with the MicroMed DeBakey Ventricular Assist Device as a bridge to transplantation

Ventricular assist device (VAD) support with pulsatile first generation pumps is a well-established therapy for bridging to transplantation. Shortcomings of this technology include limited applicability to small patients, noise, and high incidence of infection and pump malfunction. A second generation of pumps, spearheaded by the axial flow MicroMed DeBakey VAD, is in clinical trials and potentially will address these shortcomings.

Between November 13, 1998 and May 7, 2002, 150 patients worldwide underwent placement of the Micromed DeBakey VAD as a bridge to transplantation. Prospectively acquired data including demographics, adverse events and outcomes was collected. Follow up is 100% with 30.4 patient-years of cumulative support time. Mean age was 48+/-4 years and 18% were female. Twenty-three percent had prior sternotomy. Preoperatively, 25% were on balloon pump support, 20% had renal insufficiency, and 40% were on at least two inotropes with a mean cardiac index of 1.8 L/min/m2. Mean support time was 75+/-81 days. Linearized rates (events/patient-year) were: reoperation for bleeding 2.03, hemolysis 0.61, device infection 0.16, thromboembolic event 0.61, pump thrombus 0.61, and pump failure 0.13. Eight-two patients (55%) were either bridged to transplantation, recovery or are ongoing and 68 (45%) have died. Several patients have been supported as outpatients.

This initial experience suggests that bridging to transplantation can be successfully approached with a small and quiet axial flow pump that provides low incidence of device infection and pump failure. The incidence of pump thrombus and thromboembolism is being addressed by incorporation of heparin coating to all device surfaces.