Effects of beta-blockers on neurohormonal activation in patients with congestive heart failure

The effect of beta -adrenoceptor antagonists (beta -blockers) on neurohormo nal activation in patients with congestive heart failure has been the subje ct of study in numerous small clinical trials. Short term therapy with beta -blockers is associated with a variable acute neurohormonal response which may be determined by the pharmacology of the agent under study and the bas eline characteristics of the patient population. Long term therapy with bet a -blockers devoid of intrinsic sympathomimetic activity (partial agonist a ctivity) is associated with evidence of decreased plasma markers of activat ion of the sympathetic nervous system, the renin-angiotensin system, and en dothelin-1, beta (1)-selective and nonselective beta -blockers appear to be associated with evidence of decreased neurohormonal activation, with diffe rential effects on beta -adrenoceptor density. Agents with partial agonist activity appear to differ from pure antagonists, with some studies reportin g evidence of increased neurohormonal activation. The mechanisms by which b eta -blockers reduce neurohormonal activation and the clinical relevance of changes in adrenergic function to their use in the treatment of heart fail ure require further investigation.