BOSTON, Oct. 4 -- The New England Journal of Medicine has published new research showing that using a laser to drill holes in heart muscle to restore blood flow significantly reduces the pain and discomfort associated with heart disease. In this procedure, known as transmyocardial laser revascularization (TMR), surgeons use a CO2 laser to perforate the wall of the heart, cutting 15 to 30 one-millimeter-size holes to improve blood flow to the heart muscle.In the study, researchers from 12 medical centers studied 192 patients who were chosen at random to be treated using TMR or continued medical management drugs such as beta-blockers, calcium channel blockers, and nitrates. Doctors found that 12 months after the procedure, 72 percent of the TMR patients reported their angina had improved at least 2 classes, based on the Canadian Cardiovascular Society angina scale. Thirteen percent of the medically managed patients reported comparable improvement.