Effect of cardiac myosin inhibitors on cardiac structure and myocardial fibrosis in obstructive hypertrophic cardiomyopathy: a meta-analysis of cardiac magnetic resonance outcomes.
Y Lu, Y Zhu, Z Tian
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In 30 seconds
This meta-analysis pooled cardiac magnetic resonance outcomes from three randomised controlled trials involving 150 patients with obstructive hypertrophic cardiomyopathy, comparing cardiac myosin inhibitors (mavacamten and aficamten) with placebo. Treatment was associated with lower left ventricular mass index (mean difference [MD] −20.01 g/m², 95% CI −29.77 to −10.26) and maximal left ventricular wall thickness (MD −2.66 mm, 95% CI −3.53 to −1.79). Left atrial volume index also decreased. The pooled results did not demonstrate improvement in late gadolinium enhancement or a significant reduction in extracellular volume fraction, leaving effects on myocardial fibrosis uncertain.
Key findings
- Left ventricular mass index was lower with cardiac myosin inhibitors than placebo (MD: -20.01 g/m 2, 95% CI: -29.77 to -10.26, P<0.0001).
- Maximal left ventricular wall thickness decreased (MD: -2.66 mm, 95% CI: -3.53 to -1.79, P<0.0001).
- Left atrial volume index was lower with treatment (MD: -13.02, mL/m2 95% CI: -17.17 to -8.87, P<0.0001).
- No significant improvement was shown in late gadolinium enhancement or extracellular volume fraction.
Why it matters
CMR measures provide information about cardiac structure and tissue characteristics in obstructive hypertrophic cardiomyopathy. The pooled findings suggest that cardiac myosin inhibitors are associated with improvements in several structural measures, while the available results do not establish an effect on imaging markers of myocardial fibrosis. This distinction helps frame what the evidence currently supports about cardiac remodelling.
What to keep in mind
The meta-analysis included only three trials and 150 patients; heterogeneity for the left ventricular mass index result was substantial (I 2 = 67.7%).