[Assessment of the efficacy of bisoprolol administration by cardiopulmonary exercise testing in patients with heart failure].

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.