Abstract :
Long-term activation of the sympathetic nervous system exerts adverse biologic effects that are mediated through α1, β1 and β2 receptors and that contribute importantly to the progression of heart failure. As a result, β blockers are no longer considered to be contraindicated for use in these patients but instead now play a critical role in the successful management of chronic heart failure. Beta blockers have been evaluated in >15,000 patients with heart failure who have participated in placebo-controlled trials. The results of these studies indicate that, like angiotensin-converting enzyme (ACE) inhibitors, long-term treatment with β blockers can lessen symptoms and improve clinical status and can reduce the risk of death as well as the combined risk of death or hospitalization. The database supporting the use of β blockers is now as persuasive (and arguably more persuasive) than the database supporting the use of ACE inhibitors in heart failure (which comprises about 7,000 patients). Yet, the benefits of β blockers are seen in patients already receiving ACE inhibitors, suggesting that combined blockade of two neurohormonal systems (renin–angiotensin system and sympathetic nervous system) can produce additive effects.
