WEDNESDAY, Oct. 24, 2001 (HealthDayNews) -- Blood transfusions can be lifesaving for older heart attack patients who are anemic, a study finds.
The finding could change doctors' attitudes about blood transfusion for heart attack patients of all ages, says Saif R. Rathore, a lecturer in medicine at Yale University School of Medicine and a member of the group that did the study.
Physicians generally don't give blood transfusions to heart attack patients unless they have severe anemia, Rathore says. "Our study will make physicians confident about considering transfusions" for more patients, he says.
The study also will provide some solid information in an area where there is "a paucity of data" to support existing guidelines, Rathore says. One measure of anemia used in those guidelines is called a hematocrit, the percentage of the volume of a blood sample that is occupied by cells; a low hematocrit indicates anemia.
Current guidelines generally say that transfusions generally are warranted only if a heart attack patient has a hematocrit of 27 or lower, Rathore says. "We found they could be beneficial for patients with hematocrits as high as 33," he says.
The study, reported in the Oct. 25 New England Journal of Medicine, used data on nearly 79,000 Medicare patients hospitalized for heart attacks. In general, the sickest patients had the lowest hematocrits. "Lower hematocrit values were associated with more frequent in-hospital events, including shock, heart failure and death, and with an increased length of stay," the researchers report.
They looked hardest at the 3,324 patients with hematocrits of 30 or lower, who were at highest risk of dying in the 30 days after they entered the hospital. The death rate was significantly lower for patients in the group who received transfusions, and transfusions "may be effective in patients with a hematocrit as high as 33," the researchers say.
"I believe this will change the way people practice," says Dr. Lawrence Tim Goodnough, professor of medicine, pathology and immunology at Washington University School of Medicine and co-author of an accompanying editorial.
"We've been struggling about the issue of when the benefit of a transfusion outweighs the risk," Goodnough says. "There has been a whole series of consensus guidelines with very little data out there to support them. In this instance, for the first time we have an indication that patients who are not transfused do more poorly than those who are transfused."
And it seems logical to apply that reasoning to patients younger than those in the study, he says. "Why should we discriminate against people who are 64 or 63 or 62? They also need a basic minimum of blood cells," he says.
The study has limitations, Rathore and Goodnough say. It was an after-the-fact collection of data, rather than the carefully controlled trial that is the gold standard of medical practice. "In a perfect world, we would like to do a randomized trial," Rathore says. But Goodnough says the "pretty powerful observation that all who came in with a hematocrit of 33 or less did much better if they were transfused" will have a strong influence on the treatment of heart attack patients.
What To Do
People who are at high risk of heart disease can ask their doctors about any indication of anemia and the use of iron supplements or other blood-strengthening measures.
The American Association of Blood Banks offers basic information about blood transfusions. Meanwhile, the Centers for Disease Control and Prevention has some facts about anemia in this country. If you're interested in the treatment of heart attacks, visit the American Heart Association.
