The procedure, called distal microcirculatory protection, is commonly and successfully used during angioplasty in vein grafts and stenting in carotid arteries. The study, published in the March 2 issue of the Journal of the American Medical Association, found that the devices were successful in removing debris from the arteries in angioplasties during heart attacks, but it showed that there was no benefit to the patient.
"It's not entirely clear why the devices failed to improve patient outcomes, but it's possible that so much damage happens during a heart attack that distal protection is simply too little, too late," said Gregg W. Stone, M.D., director of research and education for the Center for Interventional Vascular Therapy at Columbia University Medical Center and New York-Presbyterian Hospital, and vice chairman of the Cardiovascular Research Foundation.
The study, which was conducted in 38 institutions in seven countries, examined 501 patients who were having heart attacks, half of whom received distal protection.
During angioplasty procedures, fatty deposits in the arteries can be dislodged and clog arteries further downstream. Distal protection devices use a specialized guidewire and catheter to collect and remove this debris.
The study evaluated the efficacy of distal protection devices using several measures, including evaluating patient ST segments ?a portion of the EKG that can indicate heart damage when it is elevated. The study showed that the percentage of patients who had normalization of the ST segment were the same, whether or not distal protection devices were used.
Within six months of the heart attack, patients had a comparable frequency of major adverse cardiac events regardless of wheth er or not they received the treatment.
The study also measured the size of the heart attacks by measuring the uptake of a tracer in the heart, and found that there was no difference for patients who received distal protection.
According to Dr. Stone, not using distal protection devices will reduce the cost of angioplasties during heart attacks, and could avoid potential complications caused by the devices.