THURSDAY, Dec. 5, 2019 (HealthDay News) -- Millions of Americans with heart failure take one of the family of beta blocker medications to help ease the condition. But in many cases, could the meds be doing more harm than good?
A new study found that taking beta blockers was associated with an increased risk of hospitalization for patients with a certain form of heart failure.
It's commonly called the "stiff heart" subtype of heart failure, and it accounts for about half of the 6 million cases of heart failure in the United States, the researchers noted.
Most patients with the subtype do take a beta blocker, even though it's uncertain if they are of benefit in these cases.
As the researchers explained, the drugs work by lowering heart rate and blood pressure, and they're typically recommended for treatment of patients with another form of heart failure, the "weak heart" subtype, because they're known to help those patients.
However, "a big problem with 'stiff heart' heart failure is that we don't have effective medical [drug] therapies," explained study co-author Dr. Timothy Plante. He's assistant professor of medicine at the University of Vermont's Larner College of Medicine.
"So, instead, we use the same medications that work for 'weak heart' heart failure," he said in a university news release. "Because beta blockers save lives in 'weak heart' heart failure, we assume they are also effective in 'stiff heart' heart failure patients."
However, the new study suggests that "this assumption may be wrong," Plante said.
U.S. Food and Drug Administration-approved beta blockers to treat heart failure include bisoprolol, carvedilol and metoprolol.
In their research, Plante's group tracked data from nearly 1,800 patients with stiff heart failure who were taking part in a clinical trial of a new drug. Of those patients, four out of five were taking a beta blocker.
While it wasn't designed to prove a cause-and-effect relationship, the new analysis found beta blocker use to be a risk factor for hospitalization for heart failure in these patients.
According to study senior author Dr. Markus Meyer, "Beta blocker use was associated with a 74% higher risk of heart failure hospitalizations among participants with heart failure and a normal [heart-]pump function." Meyer is an associate professor of medicine at the University of Minnesota Medical School.
Lead author Dr. Daniel Silverman, a cardiology fellow and clinical instructor in medicine at University of Vermont Medical Center and Larner College of Medicine, explained that "in 'stiff heart' heart failure, the heart is less able to relax and fill with blood. Beta blockers appear to increase pressures inside the heart. This may lead to symptoms like worsening shortness of breath and retention of fluid."
So, does this mean patients should switch to another medicine? Not yet, Meyer said.
"It is important to understand that our findings are not proof that beta blockers are harmful among patients with 'stiff heart' heart failure -- it is just a concerning signal," Meyer said. The research team believes the findings do point to the need for a clinical trial to evaluate the safety and effects of beta blockers in patients with "stiff heart" heart failure.
Two heart specialists unconnected to the study were cautious about over-interpreting the findings.
"Treatment of this group of 'stiff heart' heart failure is still very new and more precise trials are needed to really change our treatment of heart failure in this population," said Dr. Satjit Bhusri, a cardiologist at Lenox Hill Hospital in New York City. He also noted that, "currently, beta blockers have a proven positive effect on preventing future cardiac events" in heart failure patients.
Dr. James Lafferty is chair of cardiology at Staten Island University Hospital, also in New York City. He said the findings could put patients and their doctors in a bind when it comes to treating "stiff heart" heart failure.
The study suggests that "if a patient had recurring hospital admissions with heart failure and preserved heart function and were on beta blockers, a discussion should take place with their physician" about whether to continue with the drugs, Lafferty said.
However, "withdrawing beta blockers can cause 'rebound' hypertension and arrhythmias," he added, and "there are also other situations -- atrial fibrillation, recovered heart function, recent heart attack, and angina -- in which beta blockers are beneficial."
The study was published online Dec. 4 in JAMA Network Open.
The American Heart Association has more on heart failure.
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