Doctors long believed that most heart failure was caused by a weakening of the heart muscle that kept it from pumping enough blood out to the body (systolic heart failure).
In recent years, however, they have recognized a second and more common form of the disorder in which the heart can empty normally, but does not fill with enough blood (diastolic heart failure).
The result is the same - the body does not get enough oxygen-rich blood for its needs. The most common symptom is shortness of breath. Other symptoms include fatigue, swelling around the ankles and high blood pressure.
In the study involved 4,128 patients, who were at least 60 years old and were randomly placed into two groups.
One group received 300 milligrams of irbesartan, an anti-hypertensive medication marketed as AvaproTM. The other group was given a placebo.
The study showed treatment with irbesartan did not reduce the risk of death or hospitalization for cardiovascular causes among patients who had diastolic heart failure, nor did it improve any of the secondary clinical outcomes, including quality of life.
The results counter the findings of previous studies claiming that the drug may have had a potential benefit.
"Heart failure is the only cardiovascular disease on the rise," said Dalane Kitzman, M.D., a cardiologist and professor in the Department of Internal Medicine at Wake Forest Baptist, principal investigator for the Wake Forest Baptist trial site and the national coordinator for the study.
"And this newer form of the disease is increasing fastest of all. That's what makes it disconcerting - that we don't have a proven effective treatment. We sort of have to go back to the drawing board," Kitzman added.
The study appears in the New England Journal of Medicine.