Comparison of Diastolic Function Parameters After Alcohol Septal Ablation and Mavacamten Therapy in Obstructive Hypertrophic Cardiomyopathy

Cardiac myosin inhibitors have been shown to improve diastolic function in patients with obstructive hypertrophic cardiomyopathy (HCM). Comparative studies to evaluate the diastolic effects of mavacamten versus alcohol septal ablation (ASA) have yet to be examined. In this single-center retrospective analysis, we compared echocardiographic parameters of diastolic function in adult patients with obstructive HCM treated with mavacamten (n = 23) or ASA (n = 22). Baseline imaging was obtained prior to therapy, and follow-up imaging was obtained five months after ASA and or initiation of mavacamten. Left-sided filling pressures (E/e’) improved with both ASA (18.6 versus 15.3, p < 0.001) and mavacamten (17.4 versus 13.5, p = 0.01). Among patients who underwent ASA, mitral annular tissue velocity (e’) was increased at the lateral annulus (6.0 versus 6.1, p = 0.02) with a trend to improvement at the septum (4.0 versus 5.0, p = 0.14). Similarly, among patients treated with mavacamten, septal e’ was increased (6.0 versus 6.7, p < 0.01) and a trended improvement was observed for the lateral e’ (5.7 versus 7.0, p = 0.06). Mavacamten therapy was also associated with an improvement in the LA volume index (45.6 versus 34.5, p < 0.001). Patients treated with ASA were older, more likely to have used tobacco, and had greater limitation in functional status. In this retrospective analysis, ASA and mavacamten were similarly associated with improvements in echocardiographic parameters of diastolic function and left-sided filling pressures, though mavacamten had a more discernible effect on the left-atrial volume index. Larger studies are required to further characterize the relative efficacy of the two therapeutic modalities.