DEAR DR. ROACH: There once was what I thought was a promising procedure to increase blood flow to the myocardium -- transmyocardial revascularization (TMR). As a heart patient with five stents, I was particularly interested in this procedure. It appeared to show great promise. In short: What has happened to TMR? — F.S.
ANSWER: The theory of TMR was great: Use a laser to make new routes for blood to flow to the heart muscle. Initial studies showed some promise, with improvement in angina symptoms even years after the procedure. However, there are some problems. The first is that the initial procedure is dangerous. Five percent to as many as 12 percent of people did not survive the procedure. Further, the new channels opened by the laser appear to close within 24 hours of the procedure. No study has shown reduction in heart attacks or longer life in those who received the procedure. Finally, the best-done trial did not show an improvement in symptoms.
Like so much in research, this procedure showed early promise, only to fail in larger studies. However, I am sure researchers continue to try to find ways of improving the procedure to reduce the risk of the initial procedure as well as long-term outcomes. It’s still too early to tell, and way too early to use outside the research setting.
DEAR DR. ROACH: I have Parkinson’s disease. Although my medication is still working, it’s not as effective as it was. I have heard that this is the time to consider stem-cell treatment. Can you tell me if this is a good idea? — S.A.
ANSWER: Parkinson’s disease is caused by the loss of neurons (nerve calls) in a portion of the brain called the substantia nigra. Stem cells are early, unspecialized cells, capable of differentiating into any kind of cell. The theory with stem-cell treatment is that the stem cells will go into the affected part of the brain and take on the role of the damaged or destroyed cells. Some early work has been shown to be very promising.