Providing ambulatory heart failure patients with higher doses of beta-blockers significantly improved all-cause death or hospitalization, according to a multicenter, randomized, controlled trial.
The researchers found increasing the dosage of beta-blockers was more effective than reducing heart rates in this patient population.
Lead researcher Mona Fiuzat, PhD, of the Duke Clinical Research Institute, and colleagues published their findings online in the Journal of the American College of Cardiology: Heart Failure on Sept. 26. The results were simultaneously presented at the Heart Failure Society of America’s annual scientific assembly.
“This study demonstrates an important question for patient care, particularly as new agents are available for targeting [heart rate] alone,” they wrote. “Our data suggests that titrating [beta-blocker] doses should be considered as first line in clinical decision making.”
They added that “this data supports the need for a definitive randomized, controlled trial examining a dose-response relationship between [beta blocker] therapy and outcomes.”
In the HF-ACTION (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training) trial, the researchers randomized 2,321 patients with heart failure and moderate to severe left ventricular systolic dysfunction to receive exercise training or usual care.
At baseline, the groups had similar systolic blood pressure, left ventricular ejection fraction and functional capacity.
The exercise training consisted of supervised aerobic exercise at 60 percent to 70 percent of heart rate reserve three times per week and then home-based training at the same intensity five times per week. Patients participated in a total of 36 sessions.
The researchers measured heart rate after patients sat for five minutes. They considered a high heart rate as greater than 70 beats per minute and a low rate as less than 70 beats per minute. They defined a high dose of beta-blockers as more than 25 mg per day and a low dose as less than 25 mg per day.
An unadjusted analysis found that patients with a higher dose of beta-blockers and/or a lower heart rate had lower rates of all-cause death or hospitalization. After adjusting for variables that were significantly associated with the primary endpoint, a higher dose of beta-blockers was significantly associated with improved outcomes regardless of heart rate.
The researchers cited a few study limitations, including that they performed a post-hoc analysis and excluded patients who were not ambulatory. They did not evaluate changes in beta-blocker dosage and heart rate during the follow-up period and also did not identify incident atrial fibrillation.