Beta Blocker Use For Heart Failure Doubles: Still Room For Improvement

Duke University Medical Center
Monday, 17 May 2004

In one of the largest analyses of its kind, Duke University Medical Center researchers have found that the use of beta blockers for patients with heart failure or left ventricular dysfunction (LVD) has more than doubled from 1995 to 2002.

While the researchers say that the steady increase in beta blocker use over time is encouraging, they emphasize that more effort is needed in the patient-health care provider relationship to ensure greater compliance long term. This emphasis on compliance is important, the researchers continued, because numerous recent clinical trials have shown that beta blockers can cut the relative risk of death by approximately one-third for this group of patients.

The Duke researchers found in their analysis of 8,914 heart failure/LVD patients entered into the Duke Databank for Cardiovascular Disease (DDCD) that beta blocker usage increased from 29 percent in 1995 to 62 percent in 2002. However, when the researchers looked at individual heart failure patients' use of beta blockers over at least two annual follow-up evaluations, only 43 percent of patients consistently took the medication. In these patients who consistently took the medication, beta blockers bestowed a 41 percent relative mortality risk reduction. The magnitude of this benefit on survival is consistent with findings in randomized clinical trials. .

Judith Kramer, M.D., of the Duke Clinical Research Institute, presented the results of the Duke analysis May 17, 2004, at the American Heart Association's 5th scientific forum on Quality of Care and Outcomes Research in Cardiovascular Disease and Stroke.

"Many trials conducted since the 1980s have shown that beta blockers can reduce the risk of having a heart attack," Kramer said. "However, as late as the early-1990s, doctors were trained not to prescribe beta blockers for their heart failure patients. Since beta blockers reduce the force of contraction of the left ventricle, it was thought these drugs would harm these patients.

"However, the first of several definitive clinical trials reported in 1996 that beta blockers improved the survival for heart failure patients," Kramer continued. "As our study shows, the acceptance of evidence-based treatment is difficult when the new evidence is a 180-degree change from previous practice."

Beta-blockers are a class of drugs that blunt the stimulatory effects of epinephrine and norepinephrine, the so-called "fight-or-flight" hormones. By blocking the effects of these hormones, beta-blockers reduce the stress on the heart, and during exertion, they limit the increase in heart rate and so reduce the demand for oxygen.

In order to determine the usage rates of beta blockers among heart failure patients since the first pivotal clinical trial, Kramer consulted the DDCD, which has been collecting detailed clinical information on all its cardiac catheterization patients since 1969. Every Duke heart patient with documented coronary artery disease is contacted once a year following discharge from the hospital: since 1995, researchers also began asking detailed questions about medication use.

In addition to analyzing the compliance trends, the researchers looked at the specific beta blocker taken. In 1995, the generic atenolol was used by 55 percent of patients, but had dropped to 37 percent by 2002. In contrast, beta blockers that have been proven in randomized clinical trials to provide a survival benefit for patients with heart failure, such as cardvedilol and metoprolol succinate, increased from 0 percent to 10 percent and 3 percent to 28 percent, respectively, over the same period.

"The patterns of drug use show that there is a growing use of evidence-based medicines in the treatment of heart failure," Kramer said. "This pattern of drug usage suggests we are moving in the right direction despite the increased cost associated with the medication."

In fact, a recent study done by the Duke Centers for Education and Research on Therapeutics (CERTs), demonstrated that beta-blockers can reduce the overall costs associated with managing a patient with heart failure, Kramer said.

While atenolol is less expensive, its effectiveness for heart failure patients has not been proven by a specific clinical trial, as it has been for reducing blood pressure. She added that there likely won't be such a clinical trial, since generic formulations of atenolol are widely used and such a trial would be very expensive to conduct.

Those factors predicting a higher rate of beta blocker usage included patients who received an angioplasty or coronary artery bypass surgery, or who had a stroke.

"These are dramatic events that appear to catch patients' attention and make them more likely to listen to their physicians," Kramer said. "These types of events also provide an opportunity for physicians to start patients on evidence-based medicines like beta blockers."

Factors predicting lower usage included increasing age, presence of chronic obstructive pulmonary disease (COPD), asthma or the use of digoxin. "Given the established data that the elderly benefit just as much from beta blockers, we are concerned by the association between older age and lower likelihood of taking beta blockers," she said.

For Kramer, communication and the personal contact between patients and the health care team could be the most effective way of increasing beta blocker use among heart failure patients.

"It is my belief that the personal approach can be the best way to support patients and help them overcome the barriers they face, whether they are financial, medication side effects or education," she said.

To that end, Duke is planning other efforts to better understand the issues surrounding long-term patient compliance with evidence-based medicines, including a pilot project that will link Duke cardiologists and pharmacists with physicians and pharmacists out in the community. The goal is to create communication links with patients to overcome barriers, she said.

It has been estimated that there are 5 million Americans with heart failure, with 550,000 new cases diagnosed each year and more than 53,000 deaths annually. The cost of treating heart failure in 2004 has been estimated at $25.8 billion.

Kramer's analysis is part of the CERTs demonstration program, a national initiative to conduct research and provide education that advances the optimal use of therapeutics, including drugs, medical devices, and biological products. The program, which consists of seven centers and a coordinating center, is administered as a cooperative agreement by the Agency for Healthcare Research and Quality (AHQR), in consultation with the U.S. Food and Drug Administration (FDA). Duke is the coordinating center for the cardiovascular CERTs.

Other members of the Duke team were Anita Chen, Bradley Hammill, Elizabeth DeLong, Ph.D., Nancy Allen LaPointe, Pharm.D., Lawrence Muhlbaier, Ph.D., Charles McCants, Jr., and Robert Califf, M.D.

For more information, or to contact Duke University Medical Center, see their website at: www.mc.duke.edu