“There was no increase in bradycardia with higher doses of BB beta-blocker,” note the authors.
Dr. Mona Fiuzat, at Duke University Medical Center in Durham, North Carolina, and colleagues explain that it is unclear whether beta-blocker dose correlates with heart-failure outcomes. To look at that issue, the team examined data from the HF-ACTION trial of exercise training versus usual care in ambulatory HF patients with systolic dysfunction.
Among the 2331 participants, 95% were taking a beta-blocker, according to the report. With the baseline dose standardized to carvedilol equivalents, dosing ranged widely between 1 and 200 mg daily, and was changed in only 6% of the subjects during the course of the study.
The occurrence of a composite endpoint of all-cause mortality and all-cause hospitalization over a median follow-up of 2.5 years declined linearly with increasing beta-blocker dosage, from about 60% with none down to about 45% with 50 mg daily. Higher doses did not improve outcomes any further, the report indicates.
After adjustment for other variables, higher beta-blocker dose remained associated with improved outcome (hazard ratio 0.96; p=0.02), Dr. Fiuzat and colleagues found
They conclude, “These data support the current clinical guideline recommendations that BB (beta-blocker) therapy should be titrated to moderate-to-high doses as used in randomized, controlled clinical trials.”