From clinical trials to clinical practice: what we know and do not know about beta-blockers and the heart.

In the early 1980s, several lines of evidence suggested the possibility that decreasing adrenergic drive could be beneficial in patients with chronic heart failure. Clinical trials conducted in the 1990s have unequivocally shown that beta-blockade improves left-ventricular ejection fraction (LVEF) in the failing heart. Beta-blockers represent the only medical treatment that has been shown to reverse the pathological myocardial remodeling observed in patients with chronic heart failure. Beta-blockers are now a mainstay of therapy for patients with New York Heart Association (NYHA) class II and III heart disease; however, several issues remain unresolved regarding beta-blocker treatment of heart failure, including (1) the potential role of beta-blockers in asymptomatic (NYHA class I) patients; (2) the potential role of beta-blockers in patients with severe (NYHA class IV) heart failure; (3) the possibility of more rapid dose titration; and (4) the influences of sex, age, and race. Further studies evaluating the efficacy of beta-blockade in class I and class IV patients are forthcoming; the results of these trials will help to determine the role of beta-blocker therapy in patients at the extremes of heart failure (ie, asymptomatic patients and those with advanced heart failure). This article discusses the issues that still remain regarding the transitioning of beta-blockade from clinical trials to clinical practice and indicates areas in which further research is warranted. Finally, barriers to treatment are discussed as well as possible strategies for overcoming these obstacles.