ATLANTA - Duke University Medical Center researchers say a new heart attack treatment may hold promise: Give patients a quick cocktail of drugs that dissolves clots and stops them from reforming, and an hour later, perform an angioplasty to clear plaque from heart arteries that are now open.
This strategy - dubbed "facilitated angioplasty" - appears to offer a better outcome than thrombolytic treatment ("clot-busting" drugs) or angioplasty alone, or even medical therapy followed by angioplasty within several days, according to Duke cardiologist Dr. E. Magnus Ohman.
Overall results of the 528-patient SPEED trial, which stands for "Strategies for Patency Enhancement in the Emergency Department," are being prepared for publication. Ohman and his group, however, prepared results of a secondary analysis that looked at the effectiveness of facilitated angioplasty in 323 of their patients.
"We have seen some dramatic outcomes in this particular subgroup of study patients," said Ohman, the study's leader. "This seems to be a fast, safe way to open clogged arteries in patients having a heart attack, and should be studied more extensively."
Coinvestigator Dr. Howard Herrmann, from the University of Pennsylvania, prepared the results of the analysis for presentation Monday at the American Heart Association's annual scientific sessions.
In SPEED, patients having a heart attack were treated within 60 to 90 minutes after arriving at one of the 61 participating hospitals in 14 countries. They were first given two doses of reteplase, a drug that breaks up blood clots, and a loading dose and infusion of abciximab, which prevents platelets from clumping to form new clots. Both drugs are approved for use in the United States, although their combination use is still in the early stages of testing.
In the subgroup in question, the drug cocktail was followed an hour later by angioplasty, a procedure that presses plaque obstructions against the artery wall by inflating a small balloon from a catheter. Then, in most patients, a small girder-like stent was implanted into the artery wall to keep the artery open.
Ohman, Herrmann and their team of researchers found that 30 days after the heart attack, 16 percent of patients who did not have facilitated angioplasty had either died, had another heart attack, or had an urgent procedure to reopen the artery, compared with 5.6 percent of patients who had facilitated angioplasty.
According to Herrmann, the rate of clinical success - defined as freedom from death, another heart attack, an urgent cardiac procedure and bleeding - was 85 percent percent in the facilitated-angioplasty group and 70 percent for other patients. "There appear to be many potential benefits to using this combination strategy to facilitate an early angioplasty," he said.
"Unlike many treatments, facilitated angioplasty takes care of both clots and plaque," said Ohman. Cardiologists typically treat heart attacks with either thrombolytic drugs, such as reteplase, to dissolve offending clots, or primary angioplasty, to clear the plaque producing the heart attack. They don't often use both since studies from the 1980s showed patients who had both treatments in quick succession fared worse. "But that was before we had a platelet inhibitor to add to the clot-busting drugs," Ohman added. "These agents prevent platelets from aggregating, which would otherwise mean more clots."
Until now, physicians did not know whether using all three treatments together (reteplase, abciximab, and angioplasty) would increase the risk of bleeding. In fact, there was a reduced need for blood transfusion and a trend toward less bleeding in patients who received facilitated angioplasty, Herrmann said.
"This triple-threat therapy provides an exciting area for exploration," Ohman said in an interview. "We hope to confirm these promising results in a much larger population."
The study was sponsored by Eli Lilly and Co., and Centocor Inc.
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