Drugs Show Mixed Results in Advanced Heart Failure
But use of beta blockers affirmed for most
WEDNESDAY, May 30, 2001 (HealthDayNews) -- Though two trials of beta blockers in advanced heart-failure patients have come up with apparently conflicting results, the drugs will continue to be a first line of treatment, cardiologists say.
While three large, previous studies showed that beta blockers, so called because they block certain receptors on the surfaces of heart cells, generally prolong life and reduce hospitalizations for patients with mild heart failure, the two new studies tested two beta blockers against advanced, chronic heart failure.
One study of the beta blocker carvedilol over more than 10 months showed a 36 percent decrease in deaths compared to a placebo treatment. Overall, the drug reduced deaths and hospitalizations by 24 percent. The decrease was so striking that the study was cut short so doctors could begin prescribing the drug sooner.
The other study of the beta blocker bucindolol also was cut short, but for different reasons. It found no statistically significant reduction in death rates over two years between a placebo group (33 percent) and those given the drug (30 percent). However, that study found that white patients benefited while blacks did not.
"Our findings raise questions about the efficacy of these agents in blacks and in patients with more advanced heart failure, as well as about the equivalency of beta blockers," report researchers in the May 31 New England Journal of Medicine .
One thing has not changed: Beta blockers remain a good treatment for persons with milder cases of heart failure, says Dr. Eric J. Eichhorn, professor of medicine at the University of Texas Southwestern Medical Center in Dallas and leader of the bucindolol study.
And most evidence still supports use of beta blockers for severe heart failure, says Dr. Eugene Braunwald, professor of medicine at Harvard Medical School and author of an accompanying journal editorial.
He calls the bucindolol study "an outlier," which is "inconsistent with three other trials which have found benefits for patients with moderate heart failure." Braunwald says the carvedilol trial offers "unequivocal evidence" of benefits for patients with advanced heart failure.
A close look at the bucindolol study shows clear benefits for nonblack participants and improvement in many clinical measures, Braunwald says. "If the trial had gone on longer, I believe they would have shown an overall benefit," he says.
He says the trial results will not affect clinical practice because bucindolol was a not-yet-approved drug whose development was stopped because of the study.
Eichhorn says the results might be explained by "a slight patient bias," with a greater number of more severe cases of heart failure in the bucindolol study.
At any rate, Eichhorn says the bottom line "is that we need to see patients early, before their heart failure becomes clinically significant, and we have a better chance to improve the outcome."
Doctors must be alert for symptoms of heart failure in high-risk patients, such as those with persistent high blood pressure or heart valve disease, he says. And patients can help by being aware of symptoms that might warn of heart failure, Eichhorn says.
What To Do
While early heart failure may have no symptoms, warning signs usually include shortness of breath and fatigue during exertion, difficulty exercising and edema, an abnormal accumulation of fluid in the body, Eichhorn says.
Read other HealthDay articles about beta blockers.