Angioplasty After Use of Clot-Dissolving Drug : Common Heart Attack Treatment May Be Extraneous

An expensive and sometimes risky procedure that has become common practice in treating heart attack victims appears to be unnecessary in many cases, according to the results of a large, federally funded study released Tuesday.

The study found that patients treated with a clot-dissolving drug, tPA, who then underwent a popular artery-widening procedure called angioplasty did no better in the short run than those who received the drug without the additional procedure.

Dr. Eugene Braunwald, who presented the results of the 3,262-patient study at the annual scientific meeting of the American Heart Assn., said a change in practice could eliminate thousands of unnecessary angioplasties and save the Medicare program alone as much as $750 million annually.

“It’s clear that this trial has settled one of the most important questions in modern cardiology,” Dr. J. Ward Kennedy, director of the division of cardiology at the University of Washington in Seattle, said of the results.

Approximately 1.5 million Americans will experience a heart attack this year. About 540,000 of them will die, according to heart association figures. If caught early enough, heart attack can be treated with drugs like tissue plasminogen activator--tPA--capable of breaking up the clots that caused the attack.

But because many patients are left with arteries still narrowed by fatty deposits, physicians regularly refer them for immediate angioplasty. A catheter is threaded into the artery and a small balloon is inflated to widen the vessel and permit free flow of blood to the heart.

The aim of the newly reported study--part of a larger, ongoing trial of the use of so-called thrombolytic drugs in treating heart attacks--was to find out whether it is advisable to do almost routine artery widening or to hold off unless specific symptoms demand it.

The researchers found that it makes little difference.

They found that 10.9% of the 1,636 patients in the group that received both the drug and the procedure died or had a second heart attack within six weeks of the treatment, Braunwald said. Among the other 1,626 patients, most of whom received the drug alone, the figure was 9.7%. However, 16.8% of the latter group wound up getting angioplasty during the six weeks because there was clear evidence of decreased blood flow to the heart after the tPA treatment.

Braunwald said he was not ruling out angioplasty. But “as a broad national strategy,” he said, heart attack patients should receive tPA alone and be watched closely. If they then experience angina or other signs of insufficient blood reaching the heart, they should be referred for angioplasty, he said.

In a comparable, 367-patient study in Europe, Dr. Marc Verstraete of the University of Leuven in Belgium said he and other researchers found that angioplasty immediately after tPA was not only of no benefit but could actually be harmful. It was linked to higher rates of bleeding, hypertension and shock, among other things, he reported.

The studies received much attention at the meeting.

Dr. Thomas J. Ryan, a professor of medicine at Boston University, said the American trial provides “some answers to a very important health care question.” Others noted, however, that many heart attack patients are ineligible for clot-dissolving therapy because they do not receive medical care in time.

Kennedy of the University of Washington stressed the importance of getting heart attack patients help within two hours in order to minimize the damage left. Kennedy is heading a study in Seattle in which paramedics, in communication with hospital physicians, will in some cases administer tPA to patients while still in ambulances.