Objective: It is well known that long-term therapy with beta-blockers reduces morbidity and mortality, improves left ventricular function in patients with heart failure. However the effect of beta-blockade on exercise tolerance in patients with heart failure remains unclear. In the present study we evaluated effects of the addition of bisoprolol to standart therapy with a diuretic and an angiotensin converting enzyme (ACE) inhibitor on exercise capacity in patients with chronic heart failure.
Methods: We enrolled 52 patients (mean age 59+/-11 years) with stable, mild to moderate chronic heart failure and left ventricular ejection fraction of 40% or less receiving standart therapy with diuretic and ACE inhibitor. We randomly assigned patients to bisoprolol 1.25 mg (n=28) or control (n=24) groups. The drug progressively increased to a maximum dose of 5 mg per day. Cardiopulmonary exercise testing (CPET) was performed in all patients of the bisoprolol and control groups before and after 3 months from the beginning of the study.
Results: We found a significant increase in exercise duration, maximal O2 uptake (pik VO2), the O2 uptake at the anaerobic threshold (VO2-AT) and O2-pulse (pik VO2/HR), and improved functional capacity (p<0.001). Bisoprolol produced significant reduction in heart rate at rest (p=0.01) and during maximal exercise (p=0.041). In the control group no significant changes were observed.
Conclusion: The addition of bisoprolol to the standart therapy in patients with mild to moderate heart failure is well tolerated and improves functional capacity.