The FDA has approved the Excor Pediatric System (also known as The Berlin Heart), a ventricular assist device (VAD), for use as a "bridge to transplant" in children. The timing of the decision is puzzling. We've been hearing about the use of VADs in adults for decades. They are used not just as bridges to transplantation but also as a long-term organ replacement therapy akin to dialysis. Former Vice-President Dick Cheney had a VAD implanted in July of 2010, even though he had been declared ineligible for a heart transplant, and he seems to be doing well 18 months later.
The FDA decision to approve the device for children says as much about the regulation (or lack of regulation) of devices in this country as it does about the device itself. It also says something about the peculiarities of the regulation of devices in the United States and Europe.
Mechanical circulatory support has been used for children awaiting heart transplantation since the 1980s. (Del Nido et al, Circulation, 1994). In the 1980s and 1990s, the most widely used type of circulatory support was extracorporeal membrane oxygenation, or ECMO. ECMO was never approved by the FDA and was never thought to actually need approval. In fact, it had been used widely for many indications for nearly two decades before the federal government said anything about its use. Then, in 1990, the NICHD convened a consensus conference about ECMO. They brought together experts from the NICHD, the National Institute of Neurologic Disorders and Stroke, the NIH Heart, Lung and Blood Institute, the Agency for Health Care Policy and Research, and the FDA. Together, these experts concluded that ECMO was probably good, that a prospective study ought to be done, but that such a study was not mandatory. In the meantime, they suggested, ECMO centers should be regionalized, accredited, and develop guidelines for the use of this innovative technology.
One could imagine a similar trajectory for the Berlin Heart VAD. We know about as much about it today as we knew about ECMO in 1990. Like ECMO, data on the Berlin Heart has been reported to the International Berlin Heart registry. As of April, 2010, 742 patients had been treated with a Berlin Heart in 142 hospitals in 32 countries. Mean age at implant was 5 years (2 days to 17 years). Ten percent were weaned off the device, 55% went on to transplant, 26% died on the VAD, and 9% were still on the VAD. Results in recent years are even more positive. In Sweden, the mortality rate after implantation of the VAD was only 8% in 2007-2010. For most transplant centers, the VAD has become a standard part of the therapeutic armamentarium. The device was approved in Europe in the mid-1990s and in Canada in 2005.
Although the registry data is compelling, there has never been a prospective, randomized controlled trial of the Berlin Heart. And there probably never will be. As with many life support technologies, randomization is difficult because neither parents nor doctors are in equipoise. But then why did it take so much longer for the FDA to approve the device than it did for similar regulatory bodies in Canada and Europe? The answer lies in the types of post-approval regulation here and there. Here, once a device is approved, there is no more option of government regulation. In health systems with centralized regulatory authority over both the financing and the delivery of health care, utilization of new devices can be more carefully overseen after regulatory approval. It is an irony of our system - our freewheeling, free market approach may actually make it more difficult for drugs and devices to be approved than is the case in systems with more central planning and governmental oversight.