HEMODYNAMIC AND PHYSIOLOGICAL-CHANGES DURING SUPPORT WITH AN IMPLANTABLE LEFT-VENTRICULAR ASSIST DEVICE

To evaluate hemodynamic effectiveness and physiologic changes on the H eartMate 1000 IP left ventricular assist device (Thermo Cardiosystems, Inc., Woburn, Mass.), we studied 25 patients undergoing bridge to hea rt transplantation (35 to 63 years old, mean 50 years). All were recei ving inotropic agents before left ventricular assist device implantati on, 21 (84%) were supported with a balloon pump, and 7 (28%) were supp orted by extracorporeal membrane oxygenation. Six patients died, prima rily of right ventricular dysfunction and multiple organ failure. Nine teen (76%) were rehabilitated, received a donor heart, and were discha rged (100% survival after transplantation). Pretransplantation duratio n of support averaged 76 days (22 to 153 days). No thromboembolic even ts occurred in more than 1500 patient-days of support with only antipl atelet medications. Significant hemodynamic improvement was measured ( before implantation to before explantation) in cardiac index (1.7 +/- 0.3 to 3.1 +/- 0.8 L/min per square meter; p < 0.001), left atrial pre ssure (23.7 +/- 7 to 9 +/- 7.5 mm Hg;p < 0.001), pulmonary artery pres sure, pulmonary vascular resistance, and right ventricular volumes and ejection fraction. Both creatinine and blood urea nitrogen levels wer e significantly higher before implantation in patients who died while receiving support, Renal and liver function returned to normal before transplantation. We conclude that support with the HeartMate device im proved hemodynamic and subsystem function before transplantation. Long -term support with the HeartMate device has a low risk of thromboembol i and makes a clinical trial of a portable HeartMate device a realisti c alternative to medical therapy.