The effect of carvedilol on B-type natriuretic peptide and cardiac function in patients with heart failure and persistent atrial fibrillation.

OBJECTIVES

We sought to determine the relationship between changes in natriuretic peptides and symptoms as a consequence of introducing beta-blocker therapy, in patients with chronic heart failure (CHF) and persistent atrial fibrillation (AF).

METHODS

In a randomised, double-blind, placebo-controlled study involving 47 patients with CHF and persistent AF (mean age 68 years and 62% men), we analysed the individual change (Δ) in B-type natriuretic peptide (BNP) level to the introduction of carvedilol (titrated to a target dose of 25 mg twice daily, group A) or placebo (group B) in addition to background treatment with digoxin. Symptoms score, 6-min walk distance, New York Heart Association (NYHA) class, left ventricular ejection fraction (LVEF), heart rate (24-hour ECG) and BNP were measured at baseline and at 4 months.

RESULTS

LVEF (Δ median +5 vs. +0.4, p = 0.048), symptoms score (Δ median -4 vs. 0, p = 0.04), NYHA class (Δ median -33% vs. +3% in NYHA class 3-4, p = 0.046) and heart rate [Δ median 24-hour ventricular rate (VR) -19 vs. -2, p < 0.0001] improved with combination therapy of digoxin and carvedilol compared to digoxin alone, but BNP (Δ median +28 vs. -6 , p = 0.11) trended in the opposite direction. There was no relationship between the degree of symptomatic improvement or VR control and BNP response.

CONCLUSION

After the introduction of carvedilol, clinical outcome appears unrelated to BNP changes in patients with CHF and AF. Changes in BNP cannot be used as a marker of clinical response in terms of symptoms or cardiac function in this setting.