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Time course of improvement in left ventricular function, mass and geometry in patients with congestive heart failure
S A Hall1, C G Cigarroa, L Marcoux
1Echocardiography Laboratory, Dallas Veterans Administration Hospital, Texas.
Insights
Beta-blocker therapy for dilated cardiomyopathy initially reduces ventricular function but improves it by 3 months. Long-term metoprolol use reverses adverse cardiac remodeling, reducing ventricular mass and improving geometry within 18 months.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Beta-adrenergic blocking agents improve ventricular function in heart failure.
- The time course of functional improvement and long-term effects on ventricular mass/geometry are unknown.
Purpose of the Study:
- Examine the time course of ventricular functional improvement with beta-blockade in dilated cardiomyopathy.
- Assess long-term effects of beta-blockade on ventricular mass and geometry.
Main Methods:
- Serial echocardiography in 26 men with dilated cardiomyopathy over 18 months.
- Comparison of metoprolol therapy versus standard therapy, with crossover design.
- Blinded analysis of all echocardiographic data.
Main Results:
- Initial decline in ventricular function (end-systolic volume increase, ejection fraction decrease) at day 1.
- Significant improvement in ventricular function between months 1 and 3 (p=0.013).
- Left ventricular mass regression (p=0.011) and improved geometry (p=0.0001) by 18 months.
Conclusions:
- Beta-blocker therapy shows delayed improvement in systolic performance, with initial function reduction.
- Long-term metoprolol therapy reverses maladaptive cardiac remodeling.
- Significant reduction in left ventricular volumes, mass regression, and improved geometry observed by 18 months.
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.