Effects of beta blockers on symptoms and functional capacity in heart failure.

Beta-adrenergic-blocking drugs ameliorate the progression of disease that usually characterizes heart failure. All of the larger multicenter studies have demonstrated reductions in morbidity, manifested by a reduction in the number of hospitalizations and/or listing for cardiac transplantation, whereas studies with carvedilol have also reported a significant reduction in mortality. The influence of beta-adrenergic blocking drugs on the symptomatic and functional status of patients with heart failure has been more difficult to establish. Almost all trials have reported an improvement in New York Heart Association (NYHA) functional class, with few patients experiencing functional deterioration. Improvement in symptom score was reported in the Metoprolol in Dilated Cardiomyopathy (MDC) trial far patients treated with metoprolol. In patients from the US Carvedilol Heart Failure Trials Program who had heart failure from ischemic and nonischemic etiologies, both patients and physicians reported more improvement and less deterioration in an assessment of global status. More formal instruments to assess quality of life, such as the specific activity scale in the Australia-New Zealand trial of carvedilol (that recruited 30% of patients who bad improved to NYHA stage I) and the Minnesota Quality of Life questionnaire, did not seem sensitive to the clinical benefits observed in these trials. Serial exercise testing similarly does not seem sensitive to the beneficial influence of beta-adrenergic blocking drugs on disease progression, at least in relatively short-term studies.