More good news for drug therapy with beta-blockers
March 1, 1999 4 minutes read
More good news for drug therapy with beta-blockers
Success in Europe may mean acceptance at home
American physicians are hoping a European study of beta-blockers will help the medications gain more support in the United States.
The report of the Cardiac Insufficiency Bisopro-lol Study II (CIBIS-II), published in the Jan. 2 issue of Lancet, showed a 32% drop in mortality and hospitalization among CHF patients who were stable and in Class III or earlier disease.
"This is a real breakthrough," says Harlan M. Krumholz, MD, of Yale University School of Medicine in New Haven, CT, who wrote the commentary on the study. "It builds on studies that have been in existence for a long time."
It is significant that the older generation of beta-blockers was found to be very effective. Before the study, there were questions about how they would stack up against the newer generation products, says Krumholz, an assistant professor of internal medicine and cardiology as well as epidemiology and public health.
"The essential thinking is not to delay in translating it to the bedside," Krumholz adds, noting similar problems are going on with drugs like ACE inhibitors. "We want to get this going as soon as possible. In a year we want to go from 10% of the appropriate patients getting it to 80% or 90%."
To make sure that translation happens, he says doctors need to do two things:
1. Establish systems to remind them to use beta-blockers when appropriate.
2. Develop treatment plans that start patients on beta-blocker therapy when they are stable, slowly titrating them up gradually from a low dose.
In his commentary, the author notes that clinical practice guidelines need to be updated for beta-blockers, since giving them to heart failure patients may contradict how doctors have been trained.
"It’s kind of an about-face," explains Tarik M. Ramahi, MD, Yale’s director of heart failure and transplant cardiology. He says while the study comes as no surprise to those who are following the research, phasing out old concepts brings anxiety. "The challenge is translating clinical trials to clinical practice."
Ramahi says these changes take more than education. "You need to push the thinking for it. It doesn’t happen very often. It takes a paradigm shift."
Changing physician attitudes about beta-blockers, he adds, will come only if doctors are comfortable with the concept of what is happening with the physiology of the heart during drug therapy, and if patients receive education as a part of their treatment.
"It boils down to how much the patient is dependent on the sympathetic nervous system for circulation," he says.
The failing heart responds by getting larger to try to keep up with its pumping task. In the short run, it works. But eventually, it becomes a destructive path. Beta-blockers are an attempt to stop the heart from going into its panic mode.
"What you are trying to do is withdraw the response slowly. But if patients are dependent on it, it’s harder to do."
Ramahi notes patients need to be stabilized before they are put on this therapy. But the patients who are referred to his facility often aren’t stable. "Surprisingly enough, most patients are not getting proper diuresis — that is usually key to getting someone ready," he says. "They either get too much or too little." (For more on diuretic regulation, see CHF Disease Management, February 1999, pp. 16-18.)
Drug therapy then continues with proper beta-blockers, ACE inhibitors, and other medication as needed.
Another facet of this therapy is teaching the patients why the treatment is needed as well as what they should and should not expect from it. "Patients may expect to be feeling better, but this is a long-term goal," he says. In the short term, the patients may actually feel worse for the first few weeks as the therapy begins to reverse the changes in the heart that were triggered by failure.
During this time, patients can become more congested and may need their blood pressure adjusted. Ramahi says when these changes happen, the doctor also may need to adjust the patient’s ACE inhibitor or diuretics, as the elevated fluid retention may bring on more shortness of breath, edema, dizziness, and fatigue.
Ramahi says patients start feeling better and show improvement in heart function in two to three months.
Limitations of the study
Both Harlan M. Krumholz, MD, of Yale University School of Medicine in New Haven, CT, and Tarik M. Ramahi, MD, Yale’s director of heart failure and transplant cardiology, note the study is not useful as a guide to treating patients in severe heart failure.
Ramahi says to follow the lead of this study requires proper patient selection. Patients in class II to early class III are appropriate — but only if they have been stable for at least a few weeks, and their blood pressure is not too high.
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