WASHINGTON – Nearly half of people with heart failure may be receiving the wrong treatment, a Johns Hopkins study has found, and researchers say the findings could turn accepted notions of heart failure upside-down.
The study concluded that people suffering from nonsystolic heart failure may be harmed by drugs known as “beta blockers,” which are used to treat symptoms by slowing the heart. Experts have long believed that hearts with nonsystolic failure, also known as diastolic failure, contract normally but fail to refill with enough blood between beats.
The Johns Hopkins researchers noted that hearts with nonsystolic failure refilled properly but failed to push enough blood through the body, even during simple daily tasks.
“We found there was no difference in how patients filled their hearts,” said Barry Borlaug, a cardiology research fellow at the Johns Hopkins University Heart Institute and the study’s lead author. “The difference was in the ability of the heart to increase during exercise.”
Borlaug presented his findings last November at an American Heart Association conference in Dallas. He is discussing publication with a leading journal, and he said he expects an agreement by the end of the week.
The study showed that hearts patients with nonsystolic failure contracted normally but faltered during light physical activity, he said. In these patients, the pumping ability of the heart decreased 40 to 50 percent, and blood vessels did not relax normally, even when the patients used only enough energy to get dressed.
Patients with nonsystolic heart failure are often prescribed beta blockers, which inhibit blood vessels from relaxing and slow nerve impulses in the heart, decreasing the heart’s rate and strength of contraction. These effects would exacerbate the symptoms faced by a person with nonsystolic heart failure, Borlaug said.
“Based on our results, the last thing you would want to do is further slow down their heart,” Borlaug said.
Instead of beta blockers, people with nonsystolic heart failure might benefit more from pacemakers and drugs that trigger blood vessel dilation, Borlaug suggested.
American Heart Association spokeswoman Ann Bolger, a professor of medicine at the University of California, San Francisco, defended beta blockers as a treatment method, but said the study was a rare but important look into patients with a specific type of heart failure.
“What this tells us is there’s a group of patients with heart failure who we haven’t studied well,” Bolger said. “It tells us that we’d better take a closer look at these people.”
About 40 percent of the 5 million Americans with heart failure are diagnosed with the nonsystolic form, which is especially prevalent among the elderly, women and blacks. The study examined 19 elderly men and women with nonsystolic heart failure, most of whom were African-Americans from the Baltimore area.
Thousands of studies have looked at systolic failure, in which the heart does not contract properly, but only one study has examined its nonsystolic counterpart, Borlaug said. As a result, nonsystolic failure has been treated in terms of what is known about systolic.
“People use expert consensus opinions, but there are no trials to back it up,” Borlaug said. “It is believed that beta blockers are good because they slow the heart, but there are no good studies out there that show this. Our results would really take exception to that.”