‘Old Blood’ Transfusions Prove Risky For Heart: Study

Heart surgery patients who received transfusions of blood stored for over 14 days were at a significantly higher risk of postoperative complications. Also, such patients were more likely to die in the hospital than those who received newer blood, researchers at the Cleveland Clinic found.

Though several earlier studies have already unveiled the dangers of transfusing blood that is nearing its expiration date, the current study is by-far the largest enrolling 6,002 patients. The findings of the current study further add to the growing concern about the safety of transfusion practices.

In the study, the researchers at the Cleveland Clinic looked at the records of 6,002 cardiac surgery patients who received blood transfusions between June 1998 and January 2006.

About half had received blood that had been stored for 14 days or less, and the rest received blood stored for longer periods.

About 2.8 percent of the patients who received older blood died in the hospital, compared with 1.7 percent of those who received fresher blood, researchers noted.

Also, the incidence of prolonged intubation for kidney failure, breathing problems and infections were significantly higher in those who received stored for over 14 days.

On one year after surgery review, 11 percent of those receiving older blood had died, compared to 7.4 percent of those receiving fresher blood.

As blood grows older, the stored red cells undergo progressive structural and functional changes, thus losing its power to bring oxygen to tissues, Dr. Colleen Gorman Koch, lead author of the study explained. Also, as the cells age in storage, they become stickier, increasing the likelihood of a clot.

As per current recommendations by the Food and Drug Administration (FDA), blood cannot be stored for more than 42 days. But with constant blood shortages throughout the country, it often is used within few days of being donated.

However, as per a researcher quoted in the journal, "the relative risk of postoperative death is increased by 30 percent in patients given blood that has been stored for more than two weeks. These results may appear to suggest that blood should be classified as outdated earlier than current recommendations."

The study features in today’s issue of the New England Journal of Medicine.