More blood transfusions linked to lower 6-month mortality in heart-attack patients with anemia

Giving more blood to anemic patients after a heart attack may save lives, according to a Rutgers Health–led study. The study, published in NEJM Evidence, affirms research conducted in 2023 that suggested mortality rate or recurrent heart attacks were more frequent in anemic patients who received less blood.

Jeffrey L. Carson, provost and Distinguished Professor of medicine at Rutgers Robert Wood Johnson Medical School, led both studies. The 2023 trial—referred to as MINT (myocardium infarction and transfusion)—looked at transfusions in anemic patients following a heart attack.

After that 2023 trial, Carson planned a study on blood transfusions that combined data from similar trials to generate more precise estimates of treatment effects.

In cooperation with researchers in France and the United States, Carson acquired data from the four clinical trials evaluating blood transfusion in 4,311 patients with heart attacks. These trials included patients who had a heart attack and low blood count. Half the patients received fewer blood transfusions and the other half received more blood transfusions. The trials compared the frequency of death at 30 days or recurrent heart attacks and death at six months.

The results of this analysis didn’t definitively establish that giving fewer blood transfusions increased a patient’s risk of death or heart attack at 30 days, but did suggest that using fewer transfusions was associated with an increased risk of death at six months.

In the original clinical trial, a large percentage of patients had suffered a previous heart attack, heart failure, diabetes or kidney disease. The average age of participants was 72, with 45% women.

The researchers compared the frequency of the main outcome of death or recurrent heart attack at 30 days after enrollment into the trial. Although not statistically significant, the study found the frequency of mortality or recurrent heart attack was 2.4% lower when a liberal approach was used.

“The results of this analysis show that giving more blood to anemic patients with heart attacks can save lives at six months,” Carson said.

For nearly two decades, Carson has studied the implications of red blood cell transfusion strategies toward providing optimal treatment for patients. His work helped establish transfusion guidelines in 2012 used by physicians to inform patient care, updates to which were announced last year in the Journal of the American Medical Association emphasizing an individualized approach in adults and children that accounts for the patients’ underlying medical problems, patient preferences and symptoms.