Effect of beta-blocker therapy on left atrial function in patients with heart failure: comparison of metoprolol succinate with carvedilol.

Author(s): Arslan S, Erol MK, Bozkurt E, Acikel M, Gundogdu F, Atesal S, Senocak H

Affiliation(s): Faculty of Medicine, Department of Cardiology, Ataturk University, Erzurum, Turkey. sarslan@atauni.edu.tr

Publication date & source: 2007-10, Int J Cardiovasc Imaging., 23(5):549-55. Epub 2006 Dec 14.

Publication type: Comparative Study; Randomized Controlled Trial

OBJECTIVE: We aimed to compare the effects of carvedilol and metoprolol succinate on left atrial (LA) function in patients with chronic heart failure. METHODS: Thirty three patients (6 females, 27 males) who had not received beta blocker treatment previously and whose left ventricular ejection fraction was below 40% were included in this study. LA volumes were measured echocardiographically just before the time of mitral valve opening (V (max)), onset of atrial systole (p-wave at the electrocardiography = V (p)) and mitral valve closure (V (min)) according to the biplane area length method at baseline and in the 3rd month after the administration of beta blockers. NT-proBNP level was measured at the beginning and in the third month of beta blocker treatment. The first group was given carvedilol 6.25 mg/day, the second group was given 12.5 mg/day metoprolol succinate and it was increased to the tolerable maximal dose. RESULTS: LA diameter and LA V (max), V (p), V (min) decreased significantly both in carvedilol group and metoprolol group after beta blocker theraphy (P < 0.01, : P < 0.01, : P < 0.05, : P < 0.05: for metoprolol, P < 0.001, P < 0.01, P < 0.01, P < 0.01 for carvedilol). But it was increased in conduit volume (P < 0.05 for two groups). LA-passive emptying fraction, LA-active emptying fraction and reservoir fraction were no significant differences both in carvedilol group and metoprolol group after beta blocker theraphy. NT-proBNP levels were found to decrease significantly in both groups after beta blocker treatment (P < 0.001).: CONCLUSION: Our findings indicate that beta blocker treatment leads to a decrease in LA diameters and volumes, and metoprolol succinate and carvedilol had similar effects on this decrease.