What Type of b-Blocker Should Be Used to Treat Chronic Heart Failure?

The success of b-blocking agents in treating mild tomoderate heart failure has generated a debate overwhether the salutary results are strictly a class effect caused by b1-adrenergic receptor antagonism or if additional pharmacological properties of some compounds increase the efficacy inherent in all agents that block b1-receptors. The diverse adrenergic receptor activities of b-blocking agents that have been used successfully to treat chronic heart failure, the emerging role of the various adrenergic receptor pathways in the mediation of cardiomyopathic phenotypes in model systems (recently reviewed in Circulation1), and the vigor of pharmaceutical company scientific marketing all contribute to the legitimacy and decibel level of the discussion. The original, largely theoretical arguments2–4 have led to increas-ingly more rigorous tests of the hypothesis that clinically important differences exist among these agents. In this issue of Circulation, Metra et al5 report the largest of these tests t