Mechanical circulatory devices for the treatment of heart failure.

BACKGROUND

During the last four decades substantial efforts have been made in the development of effective mechanical circulatory devices. Since the first clinical utilization in the 1960s, the field has gone from the stage of clinical experimentation to that of a valid and effective heart failure treatment alternative. Experience gained during the short-term use of these devices, typically as a bridge to cardiac transplantation, has led to increased expectations of devices capable of long-term or permanent support to be used as a permanent treatment for end-stage heart failure patients. This article reviews the history, current state of the art, and future of the field of mechanical circulatory devices.

METHODS

Mechanical circulatory devices can be classified into three major categories: (1) total artificial hearts, (2) pulsatile ventricular assist devices, and (3) nonpulsatile ventricular assist devices. The most widely used devices have been the pulsatile ventricular assist devices with more than 5,800 reported cases, whereas the use of total artificial hearts has been limited to less than 350 reported cases. Nonpulsatile devices have been used clinically, but only in short-term cases (i.e., hours and days), whereas the pulsatile devices have been used in the long-term application, with patients supported for weeks, months, and in a small number of cases, years. The technological evolution of these devices has gone from large, extracorporeal systems designed to keep the patient alive in the intensive care unit (ICU) until a donor organ could be found, to portable devices that allow the patient to be mobilized outside of the hospital setting.

RESULTS

The clinical experience with mechanical circulatory devices as a bridge to cardiac transplantation has saved the lives of thousands of patients. Exciting new research discoveries related to recovery of native heart function during extended circulatory support have provided new hope for many more patients. Additional research efforts currently underway are being tested at various laboratories around the world and will soon provide the next generation of systems. These new systems will offer the recipients an unparalleled quality of life with minimal limitations on daily activities. The progress in this field has reached the point where circulatory support will soon be considered a valid long-term or permanent therapy and an elective to transplantation.