Patients with chronic heart failure, in which the heart doesn't pump as well as it ought to, often also have anemia, a deficiency in oxygen-carrying hemoglobin. Researchers at two hospitals and at Amgen, a company that makes drugs to treat anemia, looked at the role of anemia in chronic heart failure.

What the researchers wanted to know: What is the relationship between anemia and chronic heart failure?

What they did: The researchers were looking back at data from a trial of etanercept (or Enbrel), an Amgen product approved to treat rheumatoid arthritis and psoriasis. In that trial, 912 patients with chronic heart failure were randomly assigned to get etanercept or placebo. Patients in the trial had blood samples taken several times to determine if they had anemia, which is a deficiency of hemoglobin, or red blood cells.

What they found: People with less hemoglobin had worse hearts and were more likely to die or be hospitalized. It makes sense that if your heart already isn't working its best, being short on the molecules that carry oxygen around the body would make things worse. Twelve percent of the patients had low enough concentrations of hemoglobin to be considered anemic. It still isn't clear what causes anemia in heart failure patients.

What the study means to you: Maybe patients with chronic heart failure should be tested for anemia.

Caveats: Amgen clearly has an interest in finding out that anemia is a serious problem for chronic heart failure patients, so it can persuade doctors to use Amgen's anemia drugs on their patients. But that doesn't mean their data are wrong.

Find out more: This trial was originally conducted to test Amgen's etanercept (not one of their anti-anemia drugs), which had no effect on anemia.

A diagram of hemoglobin from the National Library of Medicine

Read the article: Anand, I., et al. "Anemia and Its Relationship to Clinical Outcome in Heart Failure." Circulation. July 13, 2004, Vol. 110, pp. 149-154.

Abstract online: http://circ.ahajournals.org