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From the beginning of his brilliant career, Dr. Mehmet Oz demonstrated surgical prowess in repairing valves, transplanting hearts, and opening blocked arteries. Along the way, his technological innovations helped save lives, earning the young scientist an international reputation. He developed a technique to implant the left ventricular assist device--a complex artificial heart to help keep patients alive while waiting for a heart transplant--and, in the mid-1990s, helped build one of the biggest and most active LVAD programs in the world.
Medical Update interviewed Mehmet Oz, M.D.--Irving Associate Professor of Cardiac Surgery at Columbia University, director of the Cardiac Assist Device Program and cofounder of the Complementary Medicine Program at Columbia Presbyterian Medical Center--to learn more about promising new research on the lifesaving potential of mechanical heart support devices.
Q: Could you tell us about the recent REMATCH. (Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure) clinical trial?
A: The REMATCH trial was done in a randomized setting to see if patients would survive longer with mechanical support of the heart versus medical therapy. This was a landmark trial because without convincing data, we would never be able to get the FDA and, more important, America's funding sources--private insurance as well as Medicare and Medicaid--to reimburse for patients who could be salvaged with this technology. We were approved to randomize 140 patients: half got devices and half got optimal medical management.
At the end of the trial, we found that there was a doubling in the survival rate at one and two years with the device versus medical management. The magnitude of survival was also four to five times greater than any medical therapy had ever demonstrated, which is appropriate because the invasiveness of the intervention is much greater than medical therapy, so you need a better result. Finally, we noted that the medical cohort had a two-year survival rate of almost zero, which means that severe heart failure has a prognosis equivalent to our worst cancers. Recognizing how sick these patients really are was a wake-up call to physicians.
Q: Does this study also suggest the potential of these devices as a bridge to transplant?
A: The people in this trial were not eligible for transplant, which is why they were put in the trial. But it is a good point you raise, and I would counter with the following observation.
One hundred years ago, the big battle in transportation was between the automobile--a cumbersome mechanized device that required special gas, roads, and driving skills--versus the horse, which was intuitively simpler and familiar. Although some disagree, one of the great success stories in American industry was the rubber industry's partnering with the automobile industry to lobby for roads. In the end, you had a transportation system much more powerful than the biological alternative.
Today, we are at that same point with mechanical heart support devices versus the biologic heart transplant. We need these organs immediately. Many patients are dying. The number of organs available for transplant hasn't changed in a decade despite very agggressive campaigns to get people to donate. And the subtleties of the immunoresponsiveness of xenografts is such that it would probably be simpler if I could give you a pusher plate or rotary pump that was very powerful, noiseless, and available off the shelf. You and your physician would probably opt for it.
More important, an assist device leaves your native heart in place so that as we develop new technologies, we can actually regenerate the function in many hearts. If we put a "piggyback" heart in, like a rotary pump, and keep you doing well for a year or two while we remodel the muscle of your heart, we will always have the option of removing the pump and giving you back your own heart.
Q: How do you remodel the ventricles? Would you be using gene therapy?
A: There are couple of ways to generate heart muscle. Gene therapy would be one very intelligent molecular-based approach.
One collateral benefit of the mechanical heart and heart-assist field is that we have learned more about why hearts are dying, because we can keep following the progression of their disease. As we learn more about why these conditions occur, we generate better leads about how to treat them.
I will give you an example. We may finally have a good use for anabolic steroids because they actually stimulate heart muscle cells quite nicely. Using anabolic steroids in patients on ventricular assist devices is actually a protocol now.
Devices have enabled some patients dying of heart failure to recover so well that we have been able to remove the devices, leaving their own hearts in place, and let them go home to live normal lives.
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