March 12 (HealthDay News) -- Elderly people suffering from a type of heart disease called diastolic heart failure do not seem to benefit from the commonly prescribed heart failure drugs, researchers from Cedars-Sinai Medical Center in Los Angeles report.

As the population in the United States ages, more elderly people are being treated for heart failure. But even though they make up the majority of those treated for the disease, little is known about the effectiveness of treatment, researchers say.

"We really don't have many data on heart failure patients above the age of 80," said lead researcher Dr. Ernst R. Schwarz, medical director of the Cardiac Support Program and co-director of the Heart Transplant Program at the Cedars-Sinai Heart Institute.

In their study, the researchers looked at elderly people with diastolic dysfunction. In this condition, the systolic function of the heart is normal. "That means their pump function is normal, but their relaxation is impaired," Schwarz explained.

Diastolic dysfunction is common, affecting 50 percent of all heart failure patients, Schwarz said. It is highly prevalent among the elderly and among women, but often it is not diagnosed and not effectively treated, he said.

"We really don't know how to treat these patients because the guidelines from the American Heart Association and the American College of Cardiology are based on systolic heart failure," Schwarz said. "We do not have dedicated guidelines on the treatment of diastolic heart failure."

The report is published in the March 15 issue of the American Journal of Cardiology.

For the study, Schwarz's team studied 142 people with heart failure, who averaged 87 years old. During five years of follow-up, 69 percent of them died.

The researchers found that none of the usually prescribed drugs -- including statins, angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers, beta blockers, diuretics, calcium channel blockers, nitrates and digoxin -- seemed to make any significant difference in who survived and who died.

"At least for patients above the age of 80 with diastolic heart failure, whether they are treated or not with these kind of medications does not affect their mortality or their long-term outcome," Schwarz said.

Dr. Byron Lee, a cardiologist and assistant professor of medicine at the University of California, San Francisco, appeared skeptical of the findings.

"I would be very cautious when drawing conclusions from this study," Lee said. "This is not a randomized, controlled study. The patients on the cardiovascular drugs might have been much sicker than the comparison group. Therefore, the drugs may have actually had a big impact -- keeping the sicker patients alive as long as the ones not on heart medications."

Schwarz, however, speculated that lower doses of the drugs might be appropriate for people with diastolic heart failure. In any case, he said, more research is needed, as are better treatment guidelines.

"We really don't have a clue how to treat them and how to treat them better," Schwarz said. "We are at the beginning of a learning curve to try to understand the changes in the elderly organism, which might require more caution with certain drugs, more dose adjustments. We need too look at the very elderly patient in a different way."

Dr. Gregg C. Fonarow, a professor of cardiology at the University of California, Los Angeles, said that better treatments need to be found for people suffering from diastolic heart failure.

"Patients who have heart failure with preserved systolic function represent half of the 5 million patients with heart failure in the United States," Fonarow said. "These patients face substantial risk for morbidity and mortality."

Although a number of cardiovascular medications reduce mortality in people with heart failure and reduced systolic function, no medical therapy has yet shown, in randomized clinical trials, to reduce risk in people with diastolic heart failure, Fonarow said.

"There is a critical need for more research and clinical trials to identify therapies which will be effective in patients with heart failure and preserved systolic function," he said.

SOURCES: Ernst R. Schwarz, M.D., Ph.D., professor, medicine, Cedars-Sinai Medical Center, medical director, Cardiac Support Program, and co-director, Heart Transplant Program, Cedars-Sinai Heart Institute, Los Angeles; Gregg C. Fonarow, M.D., professor, cardiology, University of California, Los Angeles; Byron Lee, M.D., assistant professor, medicine, University of California, San Francisco; March 15, 2009, American Journal of Cardiology