Anemia Drug May Worsen Heart Attacks2011-May-10
TUESDAY, May 10 (HealthDay News) -- People given a drug known as erythropoietin alfa after a heart attack may experience new heart problems and even greater cardiac damage from the attack, a new study finds.
The drug, which stimulates red blood cells, has been used in some heart attack patients because certain studies suggested it might reduce the extent of heart attack damage and improve heart function, the researchers explained.
The study was published in the May 11 issue of the Journal of the American Medical Association.
"This study shows that erythropoietin should only be used with caution in patients with recent heart attacks," said Dr. Deepak L. Bhatt, chief of cardiology at the VA Boston Healthcare System, who was not involved in the study.
In fact, "there are hints in this study that the use of erythropoietin might have adverse cardiac effects," said Bhatt, who is also an associate professor of medicine at Harvard Medical School and the author of an accompanying editorial in the journal. This does not mean the drug doesn't have its place, for example, to help reduce transfusions in people with low blood counts, he added.
Known as erythropoiesis-stimulating agents (ESAs), erythropoietin drugs include Procrit and Epogen. They are typically used to treat anemia in cancer patients and to lower the risk of transfusions.
For the new study, dubbed the REVEAL trial, 222 heart attack patients in multiple centers across the United States were randomly assigned to receive erythropoietin alfa or a placebo after undergoing a balloon angioplasty or stent placement to open blocked heart vessels.
The patients had all suffered the most critical type of heart attack -- an ST segment elevation myocardial infarction, or STEMI. Because these patients are in danger of cardiac tissue death due to a local lack of oxygen (infarct) and other changes that increase the chance of heart failure and death, the researchers wanted to see whether erythropoietin alfa might have a protective effect.
The trial was led by Dr. Samer S. Najjar, of the Med-Star Health Research Institute at the Washington Hospital Center, in Washington, D.C. As a phase 2, randomized, double-blind trial involving a placebo and control group, in which neither the patients nor the researchers knew who was getting medication or the sham treatment, it is the type of study considered the gold standard of research.
The heart attack patients taking erythropoietin alfa received an intravenous dose of the medication four hours after a primary or rescue angioplasty or stent procedure; the control group received a saline infusion. Each patient underwent two cardiovascular magnetic resonance imaging scans, one before and one after treatment with erythropoietin alfa or the placebo.
The researchers found the size of the damaged area of the heart remained the same after each scan in both the erythropoietin alfa and placebo groups.
However, among patients 70 and older given erythropoietin alfa, heart damage actually increased over the first week after treatment, the researchers said.
Moreover, five patients receiving erythropoietin alfa either died, had another heart attack or had a blockage in the stent placed during angioplasty. None of the patients receiving placebo had these problems, the researchers said.
This is not the first time Procrit and other ESAs have been linked to serious adverse events. Last year, problems with ESAs prompted the U.S. Food and Drug Administration to require tighter guidelines on them for cancer patients because of the increased risk of stroke, heart failure, tumor promotion and death seen among those taking them.
Commenting on the study, Dr. Gregg Fonarow, the associate chief of cardiology at UCLA's David Geffen School of Medicine, said that "there has been substantial interest in the development of cardioprotective agents which could be administered during acute myocardial infarction (heart attack)."
There has been a growing body of experimental data that suggests erythropoietin may have anti-inflammatory properties and other qualities that could protect the heart, but earlier studies evaluating the effects of erythropoietin have been small, with conflicting results, he added.
"These findings, together with prior studies, suggest that there are not clinically relevant cardioprotective effects with erythropoietin-stimulating agents in patients with acute myocardial infarction," Fonarow said.
For more information on ESAs, visit the U.S. Food and Drug Administration.
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