African American patients with heart failure experienced a 43 per cent improvement in survival after taking BiDil, the nitric-oxide enhancing, fixed-dose combination of isosorbide dinitrate (I) and hydralazine (H), in addition to standard heart failure therapy (P=0.01), as compared with patients in the study receiving standard heart failure therapy plus a placebo, according to the results from the African American Heart Failure Trial (A-HeFT) presented at the American Heart Association's Late-Breaking Scientific Sessions.
A 10.2 per cent death rate was shown in the placebo group compared to 6.2 per cent of patients in the fixed-dose I/H group (P=0.02). Trial results also confirm a 33 per cent reduction in first hospitalization for heart failure (P=0.001) and an improvement in the quality of life (P=0.02) for African American heart failure patients taking the fixed dose I/H therapy.
The A-HeFT trial, co-sponsored by NitroMed Inc. and the Association of Black Cardiologists Inc. (ABC), is the first study conducted in an all African American heart failure population. As reported in the New England Journal of Medicine, the primary end point for the trial was a composite score made up of weighted values for death from any cause, a first hospitalization for heart failure, and change in the quality of life. NitroMed submitted these clinical data to the FDA on November 1, 2004 and expects to file an amended new drug application for BiDil with the FDA by the end of 2004.
"African Americans suffer disproportionately from heart failure and until A-HeFT have been underrepresented in heart failure trials," said Malcolm Taylor, Chair of the Association of Black Cardiologists Committee on Heart Failure.
The 18-month randomized, double-blind, placebo-controlled study enrolled 1,050 self-identified African American patients with New York Heart Association class III and IV heart failure at 170 clinical research sites with no patients lost to follow-up over the full 18-month period. A-HeFT patients were prescribed the fixed-dose I/H (20 mg/37.5 mg) or placebo (518 fixed-dose I/H and 532 placebo), in addition to current standard heart failure treatments. This is the largest minority and female population studied in a heart failure clinical trial to date.
In July 2004, on the unanimous recommendation of the independent A-HeFT Data Safety and Monitoring Board (DSMB) and A-HeFT Steering Committee, NitroMed halted the confirmatory Phase III clinical trial of the fixed-dose I/H therapy, BiDil, due to a significant survival benefit seen with the drug. Adverse events reported in the trial included symptoms of headache and dizziness, which were significantly more frequent in the group given BiDil, and exacerbations of congestive heart failure (both moderate and severe), which were significantly more frequent in the placebo group.
Heart failure, or end-stage cardiovascular disease, affects approximately five million Americans. There is no cure for this disease, and more than 50 percent of patients die within five years of diagnosis. African Americans suffer a disproportionate incidence of cardiovascular disease. With respect to heart failure, they are affected at a rate greater than that of the corresponding non-African American population, and they present with and die from the disease at an earlier age.