EXPERIENCE WITH THE NOVACOR LEFT-VENTRICULAR ASSIST SYSTEM AS A BRIDGE TO CARDIAC TRANSPLANTATION, INCLUDING THE NEW WEARABLE SYSTEM

The three components of the Novacor left ventricular assist system, co mpact controller, battery, and back-up battery, have been miniaturized in the development of the wearable system. Therefore patients can be fully mobilized receiving mechanical circulatory support while awaitin g heart transplantation. Between February 1992 and April 1994 a total of eight patients with decompensated heart failure (6 dilated cardiomy opathy, 1 acute myocarditis, 1 ischemic cardiomyopathy) were treated w ith the Novacor left ventricular assist system. In the most recent fou r cases the wearable system (N100P) was used. Patients' ages ranged fr om 17 to 49 years. In five patients severe failure of the right side o f the heart was present at the time of implantation. Hemodynamic stabi lization was achieved in all patients during the 2 to 122 days (mean 3 0.8 +/- 42.5 days) of support. The following parameters were measured on average before and 24 hours after implantation of the left ventricu lar assist system: mean arterial pressure 70 +/- 11 versus 87 +/- 13 m m Hg (p < 0.05), cardiac index 1.71 +/- 0.42 versus 3.23 +/- 0.74 L/mi n/m(2) (p < 0.05), pulmonary capillary wedge pressure 27.1 +/- 4.4 ver sus 9.9 +/- 5.2 mm Hg (p < 0.01), mean pulmonary pressure 41 +/- 9 ver sus 27 +/- 6 mm Hg (p < 0.05), and right ventricular ejection fraction 16.7% +/- 10.3% versus 22.0% +/- 11.6% (not significant). Patients wh o received the wearable system were capable of managing their own powe r supply during the bridging period and were able to walk to the hospi tal park and shopping area. One patient had a serious pulmonary infect ion, which was treated successfully, and two patients had a cerebrovas cular accident, which resolved in one and resulted in a minor residual deficit in the other. All eight patients received a heart transplant. One patient died early after transplantation and seven patients are a live and well. In summary, the wearable Novacor left ventricular assis t system provides major advantages regarding quality of life of patien ts during mechanical circulatory support. However, there is a remainin g risk of thromboembolism despite anticoagulation therapy.