Study suggests that some patients on beta blockers should not be

A Johns Hopkins study has raised doubts about a long-accepted notion of what's going on in many cases of heart failure, suggesting that nearly half of patients with the disorder may be getting the wrong treatment for their disease.

A team of Hopkins scientists found that people with so-called nonsystolic heart failure - marked by relatively normal pumping action - do not have a problem with refilling of the heart after the heart contracts and squeezes blood out. During exercise, the heartbeat does not increase as expected, which limits the capability of these patients to pump blood to the body.

Their findings suggest that these patients might be better off without beta blockers that slow down the heart and worsen blood vessel function. Instead, they may benefit from therapies such as pacemakers to speed up the heartbeat or drugs that enhance blood vessel dilation.

The results may also help explain why some people with heart failure and relatively normal pumping ability still have severe fatigue performing the simplest of daily tasks.

Although preliminary, the findings "could dramatically change the way we initially treat patients with this kind of heart failure, because a cornerstone of current therapy is the use of beta blockers that slow down the heartbeat and decrease the strength of contraction," says lead study investigator and cardiologist Barry Borlaug, M.D.

Borlaug, a cardiology research fellow at The Johns Hopkins University School of Medicine and its Heart Institute, is scheduled to present the study results at the American Heart Association's annual Scientific Sessions on Nov. 15 in Dallas, Texas.

In the study, the Hopkins team challenged the commonly held belief that if heart- failure patients have a normal ability to pump and squeeze blood to the rest of the body, (systolic function), then by "default" their hearts have a damaged ability to relax and fill up with blood after contraction (nonsystolic, or diastolic function). More than 5 million Americans are estimated to have some form of congestive heart failure, marked by symptoms such as shortness of breath and fatigue. An estimated 40 percent are diagnosed with nonsystolic heart failure.

The Hopkins team found that when all study participants exercised at increasing levels, their hearts filled with blood in a similar way. However, heart function quickly failed to adjust to the increased activity in patients with heart-failure symptoms. At peak exercise levels, the ejection fraction, or squeezing function, was also compromised in patients whose disease was traditionally thought to be diastolic in nature. The study is believed to be one of the first to examine patients with the nonsystolic kind of heart failure by a head-to-head comparison with patients having similar features, such as high blood pressure and hypertrophied, or overgrown, hearts, but no symptoms of heart failure.