Laser Heart Therapy Brings Hope to Chest Pain Patients With Few Options
March 13, 2000 (Anaheim, Calif.) -- Three years ago, one of heart specialist Emerson C. Perin's patients was confined to a bed at a Houston hospital with nitroglycerin flowing into his vein because his chest pain "was so bad that he couldn't go to the bathroom without pain." Today, that same patient is "running his ranch, riding his tractor."
The miracle? A tiny laser, threaded deep into his heart, that drilled minuscule channels into the heart muscle, a procedure called percutaneous transmyocardial revascularization, or PTMR.
At a handful of heart centers around the country, heart specialists are researching this 'drilling' procedure that may offer new hope to a group of patients called 'no-option patients.' According to Perin, these patients have disease so advanced that traditional approaches such as bypass surgery or balloon angioplasty won't work. Until now, the only option for these patients has been heart transplant. The rancher mentioned above was actually waiting for transplant when he underwent the experimental laser procedure.
Emerson C. Perin, MD, presented results of a study that compared the laser procedure to medical management in 325 patients with disabling heart disease. The patients who underwent laser treatment significantly increased their exercise time and also had a significant decrease in their chest pain when compared with those who received standard medical therapy, he says. Perin, a clinical assistant professor of medicine at Baylor College of Medicine in Houston, presented the results here Sunday at a meeting of the American College of Cardiology.
But although Perin's results are impressive, they are far from the last word on this experimental technique. At another session here, Ran Kornowski, MD, director of the cardiac research institute at Washington (D.C.) Hospital Center, presented positive results from a small study using PTMR for similarly hard-to-treat patients with chest pain.
However, using a special imaging technique to assess how well the laser procedure achieved its goal of increasing blood flow to the heart, another group of investigators led by Robert C. Hendel, MD, failed to document any improvement in this same group of patients. These paradoxical results continue to frustrate investigators. Hendel is an associate professor of medicine at Rush Presbyterian Medical Center in Chicago.
It appears that there are more questions than answers when it comes to PTMR. Timothy Sanborn, MD, professor of medicine at Weill Medical College of Cornell University in New York, says the original theory of transmyocardial revascularization was that "one could increase blood flow by creating these channels." When it was clear that the channels close up, other theories surfaced, he says.
For example, the therapy may promote new blood vessel growth in the heart, improving blood flow. Or it may be that the laser injures nerves in the heart wall, thus blocking the ability of those nerves to send pain signals. "Or it may be a combination of various mechanisms that produce these results," Sanborn says.