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From our lengthy and extensive single-center experience in the development of mechanical circulatory support devices, we have gleaned valuable information regarding the treatment of patients with congestive heart failure. We have learned, for example, that device function must match patient need and that the timing of implantation is critical to patient survival. This important article from 1977 emphasizes this point, as it describes our initial experience with the intraaortic balloon pump (IABP)—now the most commonly used circulatory support device—including our “unsuccessful” early results. From 1972 (when we began the IABP trial) through 1974, we implanted the pump in 34 patients. Of those patients, only 2 (1 in 1973 and 1 in 1974) survived until explantation, and only 1 (the patient in 1974) survived to discharge. Yet the intraaortic balloon pump remains essentially unchanged today, and survival rates of 70% to 80% can be expected when the device is implanted in appropriately selected patients.
We also had a high mortality rate during our initial clinical trials of the abdominal left ventricular assist device (ALVAD). The device worked well both experimentally and clinically, but none of the 22 patients who were supported with it survived. That ALVAD ultimately evolved into the Heart Mate® I, which has now been implanted in more than 5,000 patients facing imminent death. Thus, the controlled trials of this device show a trend similar to that of the IABP; that is, there is a variable learning curve with any new technology used to treat terminally ill patients, which must be appreciated when such new technologies are evaluated.
Our early experience with mechanical circulatory support devices dramatically illustrates the importance of ensuring that the device under consideration is suitable for the patient and that the implant procedure is timed appropriately. In our initial trials with both of these devices, our patients were essentially moribund, and the devices were used only in a desperate attempt to save their lives. From this experience, however, we learned that the devices worked, which enabled us to intervene earlier with the correct device. Improved patient survival was the result.
Over the last 30 years, the reliability and efficacy of mechanical circulatory support devices has been demonstrated. Therefore, I believe it is inappropriate to continue the requirement that related new technologies be used only in terminally ill patients. The experience described in this report—of the first few years of IABP use and of our early ALVAD experience—shows the error in this approach, both medically and ethically. Of the first 35 IABP patients, only 1 survived. Today, using basically the same device, we would expect at least 25 patients to survive. We need to remember our history with these devices and learn from it.
This experience emphasizes the danger of premature randomized studies, which can expose technology to errors that are manmade rather than inherent.
The article that follows this commentary has been reprinted from Cardiovascular Diseases: Bulletin of the Texas Heart Institute 1977;4:428–36.