[Hormonal hyperactivity in heart failure. Differences in beta blockers].

PATHOPHYSIOLOGY

Heart failure is characterized by a disturbed contractility and activation of neurohumoral mechanisms. Activation of the adrenergic system and the beta-adrenergic signal transduction pathway leads to downregulation of beta 1-receptors of the heart muscle cell membrane.

THERAPY

In addition to ACE inhibitors, diuretics and glycosides, beta blockers are an integral part in the combination therapy of patients with heart failure. Carvedilol, bisoprolol and metoprolol have been approved for use in patients with heart failure. Carvedilol is a nonselective beta-adrenoceptor antagonist with additional alpha 1-receptor-blocking properties. Furthermore, it has additional antioxidative and antiproliferative effects. Bisoprolol and metoprolol are beta 1-selective beta blockers without intrinsic sympathomimetic activity. Based on the results of the US carvedilol trials, the CIBIS-II trial, the MERIT-HF study and the COPERNICUS study, it has been shown that beta blocker therapy can improve the prognosis of patients with compensated heart failure (NYHA II and III) and carvedilol can improve prognosis in severe heart failure (stage IV). Induction of therapy must be performed using very low doses, that can be increased in 2- to 3-week intervals. Drug dosages should be increased as much as possible. Besides a better prognosis, clinical symptoms and left ventricular ejection fraction can be expected to improve. The final effect can be expected only after months up to 1 year. Therapy should continue lifelong.

CONCLUSION

In summary, beta blocker therapy of congestive heart failure has been established as an integral part in the combination therapy of patients with all clinical stages of heart failure.