Efficacy of carvedilol treatment on cardiac function and cardiac sympathetic nerve activity in patients with dilated cardiomyopathy: comparison with metoprolol therapy.

UNLABELLED Carvedilol and metoprolol have been reported to be effective in the treatment of patients with chronic heart failure. However, to our knowledge, there have been no studies comparing the effects of the 2 drugs on cardiac function, including cardiac sympathetic nerve activity. METHODS We compared 15 patients with dilated cardiomyopathy (DCM) who were receiving carvedilol (group A) with 15 patients with DCM who were receiving metoprolol (group B). Before and after 1 y of treatment, cardiac (123)I-metaiodobenzylguanidine ((123)I-MIBG) uptake was assessed using the total defect score (TDS) and the heart-to-mediastinum (H/M) activity ratio from the delayed images. The New York Heart Association (NYHA) class and echocardiographic left ventricular ejection fraction (LVEF) also were assessed. RESULTS In both groups, the TDS decreased (in group A, from 25 +/- 14 to 16 +/- 14, P < 0.01; in group B, from 27 +/- 9 to 19 +/- 10, P < 0.01), the H/M increased (in group A, from 1.67 +/- 0.31 to 2.01 +/- 0.36, P < 0.01; in group B, from 1.68 +/- 0.21 to 1.93 +/- 0.32, P < 0.01), the LVEF increased (in group A, from 31% +/- 10% to 48% +/- 10%, P < 0.01; in group B, from 28% +/- 9% to 47% +/- 15%, P < 0.01), and the NYHA functional class improved (in group A, from 2.9 +/- 0.3 to 1.7 +/- 0.5, P < 0.01; in group B, from 2.8 +/- 0.6 to 1.7 +/- 0.6, P < 0.01). The change in LVEF was mildly correlated with the change in the TDS in group A (r = 0.41) as well as in group B (r = 0.53). In the patients with a favorable response in the TDS or H/M, the NYHA class improved more than in the patients without a favorable response (P < 0.05). CONCLUSION Carvedilol treatment can improve cardiac function, symptoms, and cardiac sympathetic nerve activity in patients with DCM to a similar extent as metoprolol treatment. The improvement of cardiac function and symptoms is related to the improvement of cardiac sympathetic nerve activity.