Study: Older blood raises heart surgery risk

Right now, it's commonplace for patients getting heart surgery to get blood that has been waiting in a refrigerator for two weeks or longer. As it turns out, this may be raising their risk of infection, kidney failure or death, according to a new report in the New England Journal of Medicine. The study, which was conducted by researchers from the Cleveland Clinic, says that cardiac surgery patients getting blood more than two weeks old were a striking 30 percent less likely to be alive a year later than peers who received fresher blood. To draw this conclusion, the researchers tracked 6,002 patients who underwent bypass or valve replacement surgery between June 1998 and January 2006. Of that group, about 3,100 received blood that had been stored for more than 14 days, while 2,900 received fresher supplies. Researchers behind the study warn that this was not a randomized clinical trial, so they're cautioning people not to see this as definitive, or to change their blood supply policies too quickly, given a serious shortage of donors nationwide. However, it does suggest the need for further studies on this subject, given that blood often sits as long as six weeks before being used.

To learn more about the study:
- read this piece from The Boston Globe

Related Articles:
Far fewer blood donors available than expected. Report
WSJ examines Red Cross's plasma business. Report