Risk of Heart Problems From Transfusions Seen

By JOHN FAUBER

Dallas American heart patients are much more likely to get a blood transfusion than those in other developed countries, a phenomenon that may put them at higher risk for heart problems, according to a recent study.

The researchers said the finding should serve as a caution to U.S. doctors to be restrained in ordering transfusions when patients might be able to increase their blood count on their own.

The analysis, which involved records from 24,000 patients, looked at transfusion rates in 16 countries in people who went to the hospital with heart attack symptoms. It was presented at the American Heart Association’s annual scientific session last month.

“We can’t say the blood transfusions are inappropriate (in the U.S.),” said lead author Sunil Rao, a cardiologist at Duke University’s Clinical Research Institute. “All we can say is, here are the numbers.’ “

The numbers showed that Americans were 84% more likely to get a transfusion than Europeans; 72% more likely than Canadians; 70% more likely than New Zealanders and Australians; and 38% more likely than Asians. The only country with a greater transfusion rate was South Africa, which was 10% higher.

Effort to use less blood

The use of blood transfusions in heart patients has become more of an issue in the last couple of years, said David Kress, a heart surgeon who practices at St. Luke’s Medical Center in Milwaukee.

“Every additional unit of blood you get is an additional risk of mortality,” Kress said.

Part of the problem is the wide availability of blood in the U.S., he said.

“It’s so plentiful that there are some physicians who dispense it like it’s a medication,” he said.

Over the last two years, there has been an effort to use less blood at St. Luke’s, he said.

That has been accomplished by raising the threshold for anemia.

As a result, the hospital is using two fewer units of blood per heart patient, he said.

Among patients undergoing bypass surgery, only 30% now require a transfusion, compared with about 45% two years ago, Kress said.

Doctors say there several reasons to limit transfusions.

Earlier, Rao and other researchers found that heart patients who got transfusions were four times more likely to die within 30 days and three times more likely to die of a heart attack than heart patients who were not transfused. That study was published last year in the Journal of the American Medical Association.

Red blood cells become inactive when blood is stored and remain so up to a day after a transfusion.

“You really aren’t helping them for a full day,” Kress said.

There also is the possibility of patients developing jaundice after getting older, banked blood, he said.

At the same time, nitric oxide, a beneficial component in blood, gets depleted in stored blood.

In addition, transfusions can cause an immune response and potentially detrimental inflammation.

“It’s not normal blood,” said Rao. “It’s completely different than the blood floating around in your body.”

Seeking answers

The new study is likely to cause U.S. hospitals to re-examine their use of blood, said Niloo Edwards, chairman of cardiothoracic surgery at the University of Wisconsin Hospital in Madison.

“They bring up some valid concerns,” he said.

However, there may be some viable reasons why transfusions are used more often in the U.S., he said.

He said patients in Canada and Europe who undergo elective heart procedures might have to wait longer than U.S. patients, who often get the procedures immediately.

The delay could give them time to stop using medications and supplements such as aspirin and vitamin E that can increase the risk of bleeding, which, in turn, might make a transfusion more necessary, he said.

In addition, in some cases if a heart attack patient does not get a needed transfusion, it can increase the severity of the heart attack, he said.

“It’s a little bit of a balancing act,” Edwards said. “Transfusion is not a bad thing. It’s a bad thing when given unnecessarily.”

Rao said the next step is to do a prospective trial looking at liberal vs. conservative transfusion methods in similar heart patients.

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