Prospects for Implantable Circulatory Support

Summary

The National Heart, Lung, and Blood Institute (NHLBI) recognizes that heart failure death and morbidity are a significant burden to society. During the period 1977–1992 the Institute supported the development of implantable ventricular assist devices designed for a 2-year lifetime. These devices have proven to be safe and clinically useful in over 1200 patients, the longest implantation exceeding 2 years. Patient quality of life seems relatively normal, requiring special attention to the implanted device but allowing complete freedom for most activities, including moderate exercise. The prospect of using implantable mechanical circulatory support (MCS) to treat heart failure is quite promising. The results with vented, implanted ventricular assist devices suggest that for some patients they may prove a long-term treatment for end-stage disease. For other patients, extended use of MCS may lead to reversal of the maladaptive remodeling processes and the restoration of normal function. Interestingly, clinical reports indicate that MCS systems may also be useful in conducting heart failure research. Towards its vision, the NHLBI is supporting programs for the implantable total artificial heart and for second-generation, innovative ventricular assist systems (IVAS) designed for a 5-year lifetime. The total artificial heart (TAH) program is beginning its final phase and the innovative ventricular assist systems (IVAS) program is nearing the end of its first year of design efforts. These results and the prospects for implantable circulatory support bespeak the talent, persistence, and continuing dedication of the worldwide pool of researchers, clinicians, and industrialists working in this field.