NHLBI is part of the National Institutes of Health. The study, "The Effect of Digoxin on Mortality and Morbidity in Patients With Heart Failure," appears in the February 20, 1997, issue of the New England Journal of Medicine.
"Digitalis has been in use for many years but its long-term safety and effectiveness had never been fully evaluated," said NHLBI Director Dr. Claude Lenfant. "These results give doctors important guidance about the drug's role in the treatment of heart failure.
"It is disappointing that digitalis was not found to prolong survival," he added. "However, digitalis can benefit patients whose symptoms are not controlled by other drugs, making them feel better and keeping them out of the hospital."
Heart failure occurs when the heart loses its pumping ability. It has been increasing in prevalence in the United States, especially among older Americans. It now affects about 4.8 million Americans, and in 1993 caused about 42,000 deaths and contributed to about another 219,000. About 400,000 new cases are diagnosed annually and about half of patients die within 5 years of diagnosis.
Heart failure is the most common diagnosis for hospitalization in patients age 65 and older. Hospitalization usually occurs because of severe symptoms, which include difficulty breathing, edema (or swelling), and sometimes abnormal heart rhythms.
Heart failure is managed with such drugs as angiotensin-converting enzyme (ACE) inhibitors, diuretics, and digitalis. Digitalis helps the heart pump by increasing the force with which its muscle cells contract.
The digoxin trial involved 302 clinics in the United States and Canada. Between 1991 and 1993, the clinics enrolled 6,800 men and women. The patients' average age was 64, and they were followed for an average of 3 years.
Trial patients had heart failure but normal heart rhythm. They also had a wide range of heart-pumping capacities. They were randomly assigned to receive either digoxin or a placebo. Nearly all were also on diuretics and ACE inhibitors.
Results show patients on digoxin had 6 percent fewer hospitalizations generally than those on the placebo and 10 percent fewer hospitalizations for cardiovascular causes. Those on digoxin who had the worst heart failure had the biggest reduction in deaths or hospitalizations for heart failure.
There were no differences in deaths from either cardiovascular disease or all causes between the digoxin and placebo groups. However, those on digoxin had fewer deaths from heart failure.
The trial was done in collaboration with the Department of Veterans Affairs Cooperative Studies Program.
Available for comment is Dr. Richard Gorlin, Senior Vice President, Mount Sinai School of Medicine, New York, and chair of the study's steering committee. He can be reached at (212) 241-9623.
NHLBI spokespersons are also available. Call the Communications Office at (301) 496-4236.
NHLBI press releases, fact sheets, and other materials are available online at the following website: http://www.nhlbi.nih.gov/nhlbi/nhlbi.htm.