Blood transfusions for anemic elderly heart attack victims can save lives, a Yale study has found.

Dr. Harlan Krumholz, an associate professor at the Yale School of Medicine, led a research team that concluded if this advice is widely accepted, thousands of lives could be saved each year in the United States alone.

“There had been relatively little guidance on this issue before in the literature,” Krumholz said. “We have been interested for a long time in improving clinical decision-making.”

Anemia is defined as a deficiency of oxygen-carrying red blood cells in the bloodstream. During a heart attack, when the heart is deprived of oxygen, anemia can make the situation even worse.

When caring for heart attack victims, therefore, treating anemia may be as important as other current treatments such as clot-dissolving drugs or an aspirin regimen.

The benefits of a transfusion are even more pronounced in severely anemic patients.

“[The importance of blood transfusions] hadn’t been widely appreciated before,” Krumholz said.

In healthy patients, however, the study raised the possibility that a transfusion can be harmful.

Especially common in older patients, anemia is a condition for which doctors routinely check. But there had been no consensus about how this information should be used.

“We wanted to eliminate the variation in practice [of whether transfusions were given to heart attack victims],” Krumholz said. “Up to this point, it was based solely on doctors’ experiences, which can vary widely.”

The Yale study, the first of its kind, used a Medicare patient database to look at the records of 78,974 patients treated for a heart attack between 1994 and 1995. The results, which confirmed a link between anemia treatment and heart attack survival, were published in Thursday’s New England Journal of Medicine.

“There is a paucity of research about the elderly,” said Krumholz, adding that this surprised him a good deal, since the elderly make up a large percentage of patients.

“We wanted to generate knowledge that will improve care for previously understudied patients, often the most vulnerable patients,” he said.

The study suggests that transfusions are helpful if the heart attack victims’ red blood cell count is below 33 percent. In the study, about 10 percent of the patients fit into this category.

The study also found that doctors often shied away from giving a blood transfusion unless the patient had a severe case of anemia. Overall, only about one in four patients who had a count under 33 percent received a transfusion.

But the study also raised the possibility that a transfusion could be harmful, if given to patients with a red cell levels above 36 percent.

Krumholz and Brown University’s Dr. Wen-Chih Wu, the first author of the study, said they hope their findings will result in a change in clinical practice.