Beta-blockers in heart failure: is more better?

Therapies that modulate the sympathetic nervous system and renin-angiotensin-aldosterone system reduce morbidity and mortality in patients with heart failure. However, they are grossly underused in clinical practice; when used, the doses prescribed are substantially smaller than the target doses used in the large-scale studies that established their utility. Whether these suboptimal doses are as effective in reducing morbidity and mortality is largely unknown. This review focuses on the relationship between the dose of b-blockers and their effect on clinical outcomes. Because direct dose comparisons of b-blockers are limited, we draw upon a broader spectrum of clinical trials across the cardiovascular continuum that involved neurohormonal modulators to address the question, "Is more better?"