Heart attack patients who receive a blood transfusion have a greater risk of dying or suffering a second heart attack according to a new study Heart attack patients who receive a blood transfusion have a greater risk of dying or suffering a second heart attack according to a new study
Heart attack patients who receive a blood transfusion have a greater
risk of dying or suffering a second heart attack according to a new studypublished in the Archives of Internal Medicine.
Researchers found the risk of death was 12 percent higher for people who
received transfusions during a heart attack compared to those who did
not. They also were twice as likely to have another heart attack.
Doctors often order blood transfusions for heart attack patients with
anemia to help deliver oxygen to the heart. But researchers say there’s
been insufficient study on the benefits and risks of the practice,
leaving doctors with little guidance on whether or not to order the
transfusions.
A team led by Saurav Chatterjee, MD, of Brown University, evaluated ten
studies carried out between 1966 and 2012 involving more than 200,000
heart attack patients. One study was a randomized trial; the others were
observational studies.
“One of the things that struck us is that there were very few studies in
evidence of transfusion at all,” Chatterjee said. “In our case, though,
we found that the effect was pretty consistently harmful across the
spectrum of studies, spectrum of time, and spectrum of patients that
were enrolled in the individual studies. “
While some transfusions are necessary, like when a patient’s suffers
both a heart attack and bleeding, Chatterjee said they also increase the
risk of blood clotting when platelets clump together or an inflammatory
immune response to the introduction of a “foreign” source into the
body.
“What we found is that the possibility of real harm exists with
transfusion,” Chatterjee said. “It is practiced in emergency departments
all across the United States. I think it is high time that we need to
answer the question definitively with a randomized trial.”
But Chatterjee also cautions that transfusions should not be stopped
altogether for anemic heart attack patients. He says doctors must
continue exercising their clinical judgment, at least until results from
a large, well-designed randomized trial can be produced.
“Before a definitive trial is out there, we should be conservative, especially considering the high risk of harm,” he said.
In a commentary also appearing Archives of Internal Medicine, Dr.Jeffrey
Carson of the University of Medicine and Dentistry of New Jersey and
Dr. Paul Hébert of the Ottawa Hospital Research Institute, question the
study’s conclusion.
“Do blood transfusions kill more patients with an acute myocardial
infarction (heart attack) than anemia? Chatterjee and colleagues would
have you believe that they do. We remain unconvinced,” they wrote.
Carson and Hébert say that because of the study’s many limitations,
doctors should not use its findings to justify or limit the use of red
blood cells. But, like Chatterjee, they also called for more studies to
be done.
“We can now appreciate how little reliable information is available to
inform clinical and policy decisions involving red blood cell
transfusions in patients with acute coronary syndrome,” they said.
“Given that real risks and potential benefits exist as to how we choose
to use the valuable resource of blood transfusion, we believe that
high-quality research is long overdue.”
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