Beta blockers in heart failure

The efficacy of beta-blocking drugs in the treatment of chronic heart failure remains controversial. A major obstacle to their acceptance in this pharmacotherapeutic role has been their reputed negative inotropic effects and the resulting depression of cardiac function when given acutely to patients in heart failure. However, in a number of uncontrolled studies in patients in mild or moderate heart failure due to dilated cardiomyopathy, these drugs, when titrated from a low-dose starting point, have been shown to improve the surrogate endpoints of symptoms and certain haemodynamic parameters. It is presumed that this benefit is related to the improvement in myocardial contractile activity secondary to the gradual up-regulation of the depressed myocardial beta-receptors in patients with chronic heart failure. At present, the data regarding the improvement in exercise tolerance are conflicting and there are no published data on the influence of beta-adrenoceptor-blocking drugs on survival. The potential of beta-blocking drugs to improve the clinical state in some patients with heart failure is, however, being further explored in two prospective randomized trials.