Future directions of cardiac assistance.

During the past decade, mechanical circulatory support has gained increased acceptance as a treatment for patients with severe heart failure who are unresponsive to conventional treatment. Steady progress has been made with respect to technology, patient selection, and postoperative management. Currently, a wide array of circulatory assist pumps offers various levels of assistance and degrees of postoperative mobility. These devices not only save lives (lowering the mortality of heart transplant candidates by 55%) but, in some long-term bridge-to-transplant cases, permit hospital discharge and cardiac rehabilitation. More than 4000 patients have been supported by long-term assist pumps worldwide. In addition to being used for bridging to transplantation or bridging to the use of some other bridging device, long-term circulatory assist devices are being evaluated as bridges to recovery or alternatives to transplantation in selected patients with severe heart failure. Moreover, several total artificial hearts have shown considerable potential in calves and will soon undergo clinical trials aimed at permanent heart replacement. Eventually, as cardiac support or replacement devices become smaller, more durable, and less obtrusive, they may become as conventional and commonplace as pacemakers are today.