Metoprolol therapy improved ventricular function between months 1 and 3 (p=0.013) and reduced left ventricular mass from 333 to 275 g by 18 months (p=0.011).
RCT (n=26)
Blinded outcome assessment
Does metoprolol improve ventricular function, mass, and geometry over time in men with dilated cardiomyopathy?
Metoprolol therapy in heart failure initially causes a mild reduction in systolic function, followed by improvement after 1 month and long-term reversal of maladaptive remodeling by 18 months.
p-value: p=0.013
OBJECTIVES: We examined the time course of ventricular functional improvement in patients with dilated cardiomyopathy who received beta-blockade and the long-term effects of beta-blockade on ventricular mass and geometry in these patients. BACKGROUND: Previous studies have shown that beta-adrenergic blocking agents when administered long term improve ventricular function in patients with heart failure. However, the time course of improvement in ventricular function and the long-term effects of beta-blockade on ventricular mass and geometry are not known. METHODS: Twenty-six men with dilated cardiomyopathy underwent serial echocardiography on days 0 and 1 and months 1 and 3 of either metoprolol (n = 16) or standard therapy (n = 10). At 3 months all patients on standard therapy were crossed over to metoprolol, and late echocardiograms were obtained after 18 +/- 5 (mean +/- SD) months of metoprolol therapy. All echocardiograms were read in blinded manner. RESULTS: Patients treated with metoprolol had an initial decline (day 1 vs. day 0) in ventricular function (increase in end-systolic volume and decrease in ejection fraction). Ventricular function improved between months 1 and 3 (p = 0.013, metoprolol vs. standard therapy). Left ventricular mass regressed at 18 months (333 +/- 85 to 275 +/- 53 g, p = 0.011) but not at 3 months. Left ventricular shape became less spherical and assumed a more normal elliptical shape by 18 months (major/minor axis ratio 1.5 +/- 0.2 to 1.7 +/- 0.2, p = 0.0001). CONCLUSIONS: Patients with heart failure treated with metoprolol do not demonstrate an improvement in systolic performance until after 1 month of therapy and may have a mild reduction in function initially. Long-term therapy with metoprolol results in a reversal of maladaptive remodeling with reduction in left ventricular volumes, regression of left ventricular mass and improved ventricular geometry by 18 months.
Hall et al. (Sat,) conducted a rct in Dilated cardiomyopathy (n=26). Metoprolol vs. Standard therapy was evaluated on Ventricular function improvement between months 1 and 3 (p=0.013). Metoprolol therapy improved ventricular function between months 1 and 3 (p=0.013) and reduced left ventricular mass from 333 to 275 g by 18 months (p=0.011).