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Treating heart attack victims with radio waves helps reduce the likelihood that implantable defibrillators will need to jolt ailing hearts into beating properly, researchers reported last week.
The radio-wave technique involves sending a probe into the heart, finding scar tissue from an earlier heart attack, and using radio waves to destroy the portion of that scar that can catastrophically disrupt the heartbeat.
A team led by Dr. Mark Josephson of Beth Israel Deaconess Medical Center found that 64 heart attack patients who were first treated this way were less likely to develop a deadly rhythm than another 64 also given an implantable cardioverter defibrillator, or ICD, but who were not treated with radio ablation. After about two years, 31 percent of the volunteers who only received a defibrillator experienced at least one shock compared with just 9 percent of those who first received the radio-wave treatment.
"We seal off the excitable tissue in the heart so it can't cause problems in the rest of the heart," Josephson said in a telephone interview.
Seventeen percent of those who only received the defibrillators died compared with 9 percent who also had their heart scars remodeled by the radio-wave therapy.
But because of the small numbers of people involved in the test, the 41 percent reduction in deaths was not regarded as statistically significant and needs to be confirmed by a larger study.
"If we showed this could really reduce mortality, then we could think of it as a primary strategy," Josephson said.
Current guidelines call for ablation only if drug therapy or defibrillator reprogramming does not prevent multiple shocks. The study did not look at patients who were on drugs to maintain a normal heart rhythm.
Even without a dramatic difference in the death rate, the findings may be important because the painful jolts that keep defibrillator patients alive can be deeply disturbing.
About half the patients who receive them develop anxiety and depression, the researchers wrote in the New England Journal of Medicine, where the study appeared.
Josephson said the problem is that ablation "takes a lot of skill. It's much easier to put a device in. However a device is no free lunch because a device has side effects" including inappropriate shocks, infection and mechanical problems.
"What the device does is rescue. This prevents the problem in the first place," he said.
But in a commentary also published in the journal, Dr. Mark Estes of the Tufts University School of Medicine said some people who receive an implantable defibrillator "may not reap enough benefit from ablation to justify the cost and risk" of the radio-wave treatment.
© Copyright 2007 Globe Newspaper Company.
