Related Experiment Videos
Improvement of exercise capacity and left ventricular diastolic function with metoprolol XL after acute myocardial
S H Poulsen1, S E Jensen, K Egstrup
1Section of Cardiology, Department of Medicine, Haderslev Hospital, Denmark. steen.hvitfeldt@dadlnet.dk
Insights
Metoprolol XL improved exercise capacity in patients post-myocardial infarction. This enhancement in physical function appears linked to better left ventricular diastolic filling, a key indicator of heart health.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Left ventricular (LV) diastolic function is crucial for exercise capacity.
- Beta-blockers enhance exercise capacity and LV diastolic function in severe systolic dysfunction.
- Limited data exists on metoprolol XL's impact on exercise capacity and LV diastolic function in mild to moderate LV systolic dysfunction post-myocardial infarction.
Purpose of the Study:
- To investigate the effect of metoprolol XL on exercise capacity.
- To assess the relationship between metoprolol XL's impact on exercise capacity and LV diastolic filling.
- To evaluate these effects in patients with mild to moderate LV systolic dysfunction following acute myocardial infarction.
Main Methods:
- A randomized, double-blind, placebo-controlled study involving 59 patients with mild to moderate LV systolic dysfunction post-myocardial infarction.
- Patients received either metoprolol XL (n=29) or placebo (n=30).
- Exercise capacity and LV diastolic filling were assessed using bicycle ergometry and Doppler echocardiography at baseline and after 3 months.
Main Results:
- Metoprolol XL significantly increased maximal exercise capacity compared to placebo (P <.01).
- Significant improvements in LV diastolic filling were observed with metoprolol XL, including decreased E/A ratio, increased A peak velocity, decreased reverse pulmonary flow, and prolonged deceleration time.
- Changes in deceleration time and A peak velocity strongly correlated with improvements in exercise capacity in the metoprolol XL group.
Conclusions:
- Metoprolol XL treatment for 3 months enhances exercise capacity in patients after acute myocardial infarction.
- The observed increase in exercise capacity is associated with improvements in left ventricular diastolic filling.
Background:
Left ventricular (LV) diastolic function predicts and correlates with exercise capacity. Beta-blockers improve exercise capacity and LV diastolic function in patients with severe LV systolic dysfunction in dilated cardiomyopathy. However, information on the effect of metoprolol XL on exercise capacity in relation to LV diastolic function in patients with mild to moderate LV systolic dysfunction after acute myocardial infarction is limited.
Methods:
In a randomized, double-blind, placebo-controlled study of 77 patients, a subgroup of 59 patients with mild to moderate LV systolic dysfunction after acute myocardial infarction were given metoprolol XL (n = 29) or placebo (n = 30). The effects of metoprolol XL on exercise capacity in relation to effects on LV diastolic filling were studied. Two-dimensional Doppler echocardiography and maximal symptom limited bicycle test were performed on days 5 through 7 and after 3 months.
Results:
Maximal exercise capacity increased in the metoprolol XL group (124 +/- 30 W vs 135 +/- 29 W) compared with placebo (125 +/- 31 W vs 126 +/- 34 W) (P <.01). E/A ratio decreased, A peak velocity increased, reverse pulmonary flow decreased, and deceleration time was significantly prolonged in the metoprolol XL group. A significant correlation was found between the changes of deceleration time (metoprolol XL: rho = 0.69, P <.0001; placebo: rho = 0.31, P = not significant) and A peak velocity (metoprolol XL: rho = 0.71, P <.0001; placebo: rho = -0.15, not significant) in relation to changes of exercise capacity.
Conclusion:
Metoprolol XL increases exercise capacity after 3 months, and this change seems related to improvement of LV diastolic filling after acute myocardial infarction.