The results were so favorable that investigators halted the multi-center trial so that all the 1,050 study participants suffering from advanced heart failure, including those on a placebo, could be given the combined drug treatment, said Dr. Clyde Yancy, a study author and director of the Congestive Heart Failure/Transplant Program at UT Southwestern/St. Paul University Medical Center.
"We discovered that patients were indeed living longer and that their incidence of death was dramatically less," said Dr. Yancy, professor of internal medicine.
A 43 percent decrease in the one-year mortality rates among African-Americans in the study receiving the combined treatment was observed by Dr. Yancy and his UT Southwestern colleagues, working in conjunction with University of Minnesota researchers. Participants, which included patients 18 years of age and older who had a heart failure diagnosis for at least three months, were recruited from 161 medical centers.
Dr. Yancy said the findings, published in the Nov. 11 edition of The New England Journal of Medicine, will have a substantial impact on the treatment of cardiovascular disease for African-Americans.
"Heart disease is the leading cause of death in the African-American community," Dr. Yancy said. "We were trying to find the best treatment for a disease that happens to be in a specific population."
The clinical trial, called the African-American Heart Failure Trial, or A-HeFT, used a combination of hydralazine and isosorbide dinitrate, two older drugs that had been used in the past to treat various heart conditions and are now being used in a new combination called BiDil.
In addition, study participants must have received standard therapy for their heart disease including beta blockers and diuretics.
The study began in June of 2001 and was discontinued on July 19, 2004, because the results were markedly favorable in decreasing mortality in the group taking BiDil as opposed to the group taking placebos.
By narrowing the focus of the study to a specific group of patients, Dr. Yancy said, the researchers could better assess the medicine's efficacy within that group. The findings, he added, provide strong evidence BiDil can slow the progression of heart failure in addition to decreasing death rates among African-American patients. Earlier heart drug studies have shown a marked difference in the drugs' effects in African-Americans and other ethnic population groups.
"Heart disease affects so many people and adds such a tremendous burden on the quality of life," Dr. Yancy said. "It is our hope that this treatment will allow patients with heart disease to enjoy a higher quality of life."
Dr. Anne Taylor of the University of Minnesota was the study's lead author. Other researchers from the Veterans Affairs Medical Center in Washington, D.C., Wake Forest University School of Medicine, Heartbeats Life Center and Xavier University; the Association of Black Cardiologists and NitroMed, Inc. also contributed.
The study was funded by NitroMed, Inc. of Lexington, Mass.