LV Remodeling Reversed among Patients with Asymptomatic Systolic Dysfunction with Metoprolol

July 6, 2007 By Erin Lord [mailto:elord@perfuse.org]

Boston, MA, USA: Higher doses of metoprolol may improve left ventricular function among patients with asymptomatic systolic dysfunction when compared with lower doses of the ß-blocker and placebo, according to results of the REVERT (The REversal of VEntricular Remodeling with Toprol-XL) trial, published this week in Circulation.

The REVERT study was the first randomized, controlled trial that examined the benefit of beta-blockers in patients with asymptomatic LV systolic dysfunction. Patients with mild LV dilatation (LV end-diastolic volume index > 75 mL/m²), a LVEF < 40%, and no symptoms of heart failure for at least two months were enrolled. The trial randomized 149 patients into three treatment groups, which were all similar with respect to baseline characteristics (200 mg metoprolol, n=48; 50 mg metoprolol, n=48; and placebo, n=53).

At 12 months, Colucci et al found that patients in the 200-mg group saw a 6±1% increase (least square mean ± SE) in LV ejection fraction and a 14±3 mL/m² decrease in end-systolic volume index (P<0.05 versus placebo and baseline). However, there was no difference in end-diastolic volume index between the 200-mg group and the placebo group, although there was a decrease when compared with the baseline measurement (P<0.05). Patients in the 50-mg group saw no change in the end-systolic and end-diastolic volume indexes when compared to the placebo group, but saw a 4±1% increase in ejection fraction (P<0.05 versus placebo and baseline).

One limitation of the study is that after withdrawal of metoprolol therapy, LV dimensions were not measured again. Because these dimensions were not calculated, the findings of the trial could be attributed to the temporary decrease in heart rate that occurs with ß-blocker therapy. However, Colucci et al argue that the improvements in the LV function with the use of metoprolol cannot be attributed to the slowing of the heart rate.

The REVERT trial was funded by AstraZeneca.


 * 1) ref1 pmid=17576868