Abstract 10336: Attenuation of Left Ventricular Fibrosis by Losartan in Patients With Nonobstructive Hypertrophic Cardiomyopathy: A Randomized, Placebo Controlled, Double Blind Study
Introduction: Despite evidence that left ventricular (LV) hypertrophy and fibrosis are mediated by angiotensin II and are important determinants of morbidity and mortality in hypertrophic cardiomyopathy (HCM), no prior study has evaluated the effects of angiotensin receptor blockers (ARBs) with cardiac magnetic resonance imaging (CMR).
Hypothesis: Treatment with losartan attenuates the progression of both myocardial hypertrophy and fibrosis in patients with nonobstructive HCM.
Methods: In a double-blind fashion, 20 patients (3 women; age 51±13 years) with HCM were randomly assigned to receive placebo (n=9) or losartan 50 mg twice a day (n=11) for 1 year. Patients with LV outflow tract gradient ≥ 30 mmHg at rest or with Valsalva maneuver were excluded. CMR was performed at baseline and 1 year to measure LV mass and extent of fibrosis as assessed by late gadolinium enhancement (LGE). Percent changes between the values at baseline and 1 year were calculated and the independent 2-sample t-test or Mann-Whitney-Wilcoxon test was performed as appropriate for data distribution.
Results: No significant baseline differences between the groups or adverse effects were observed. Seven patients had no LGE at baseline and 1 declined CMR. There was a trend towards a significant difference in the percent change in LV mass (median [interquartile range], +5 [-4, +21] % on placebo vs. -5 [-11, -0.9] % on losartan; p=0.06; Figure 1A). There was a significant difference in the percent change in extent of LGE (mean ± standard deviation, +31 ± 26 % on placebo vs. -23 ± 45 % on losartan; p=0.03; Figure 1B). There was no relationship between the change in systolic blood pressure and the change in LV mass or extent of LGE at 1 year.
Conclusions: This study demonstrates attenuation of progression of myocardial fibrosis by losartan in patients with nonobstructive HCM. Verification of our results in a larger trial is required to confirm a place for ARBs in the management of HCM.
- © 2013 by American Heart Association, Inc.