Implantable electrical left ventricular assist systems: Bridge to transplantation and future

An implantable left ventricular assist system (LVAS) utilizing an electromechanically driven dual pusherplate blood pump has been employed in a multiinstitutional trial as a bridge to cardiac transplantation. Under development for permanent circulatory support in patients with end-stage heart disease, the LVAS, in this application, derives power and control from an external console via a percutaneous lead. The LVAS was implanted in 20 patients (16 men, 4 women) who were hemodynamicaliy unstable or in refractory cardiogenic shock. The mean age was 44.9 years (range, 25 to 63 years). Preoperative diagnosis was evenly divided between end-stage ischemic disease, cardiomyopathy, and acute myocardial infarction. Implanted in the left upper quadrant within the anterior abdominal wall, the blood pump was connected between the left ventricular apex and ascending aorta. Total support of the systemic circulation and substantial left ventricular unloading were achieved with synchronous counterpulsation for periods up to 90 days (mean, 22.7 days). All patients were stabilized hemodynamicaliy. The mean preoperative cardiac index of 1.5 L/min/m² increased by a factor of 2. Pulmonary arterial pressures decreased substantially. Serious complications occurred in 16 patients, precluding cardiac transplantation in 10. Most complications (> 70%) were in patients who did not receive transplants; the most common complication was bleeding. Twelve of 13 patients with LVAS implants for more than seven days were mobilized, and 4 were fully ambulatory and completely rehabilitated. Orthotopic cardiac transplantation was performed in 10 patients after implants ranging from two to 90 days (mean, 30.3 days). Two patients died perioperatively, 1 of presumed sepsis and the other of donor-organ failure. Eight patients who received transplants were discharged and have been followed for 1 to 47 months (mean, 15.9 months). There have been no late deaths: 3 patients are working, 1 is a housewife, and all are in New York Heart Association functional class I. The bridging procedure provides an ideal setting for the initial clinical evaluation of, and offers an encouraging view of, the fully developed permanent LVAS.