Avapro Blood pressure drug fails heart failure trial

NEW ORLEANS (Reuters) - The blood pressure medicine Avapro, sold by Bristol-Myers Squibb Co and Sanofi-Aventis, was no better than usual care in treating a type of heart failure that primarily affects women and the elderly, according to results of a large study.

Researchers had hoped to show that Avapro could reduce the incidence of death and serious heart problems better than medicines currently used in this patient population that only treat symptoms of the disease.

There was a small advantage with Avapro in the study's composite goal of reducing death from any cause and hospitalization for heart attacks, strokes, heart failure, unstable angina or arrhythmia compared with usual care, but it was not statistically significant, researchers said.

"We were particularly disappointed because we still have large numbers of patients that still don't have a good treatment," said Dr. Barry Massie, who presented the data at the American Heart Association scientific meeting here on Tuesday.

The 4,128-patient study tested those with the type of heart failure in which the heart pumps well and is not enlarged, yet still causes classic symptoms such as fluid retention, shortness of breath and swelling.

Massie, a professor of medicine at the University of California, San Francisco, said up to half of the 5.3 million Americans who suffer from heart failure have this type of the disease called preserved ejection fraction heart failure.

"This is a large population and unfortunately we have not had any specific therapy to treat the underlying condition," Massie said. Instead patients are given drugs to treat symptoms such as blood pressure medicines for hypertension and diuretics to lessen fluid retention.

In healthy people, about 55 percent of the blood in the left ventricle, the heart's main pumping chamber, is squeezed out with each contraction.

With the more commonly thought of type of heart failure, a far smaller percentage of blood is pumped per contraction, and therefore called low ejection fraction. But patients studied in the Avapro trial have a near-normal ejection fraction called preserved ejection fraction.

"These are older and disproportionately female patients who usually have a long history of hypertension," Massie said.

More than a third of the participants in the study were older than 75; 60 percent were women and the majority had high blood pressure.

Patients in the study received either their usual medicines and Avapro, or a placebo on top of their other treatments, such as hypertension drugs like ace inhibitors and beta blockers.

Avapro, known chemically as irbesartan, belongs to a class of blood pressure drugs called angiotensin II receptor blockers, or ARBs.

Because a majority of patients with preserved ejection fraction heart failure have high blood pressure it was hoped Avapro could improve outcomes in study subjects who were followed for 4-1/2 years.

But earlier studies using other blood pressure medicines in this patient population also failed to help patients more than conventional treatment, so the results, while disappointing, were not particularly surprising.

"This was an important study because ace inhibitors and ARBs are already widely used even though no clinical trial has shown a benefit," said Margaret Redfield of the Mayo Clinic, who critiqued the study at the AHA meeting.

"We really need more studies to understand what's going on with these patients," she said.

(Editing by Dave Zimmerman and Maureen Bavdek)