Focused Transthoracic Echocardiogram Surveillance Protocol for Hypertrophic Cardiomyopathy Patients on Mavacamten Therapy

Serial two-dimensional transthoracic echocardiograms (TTE) are critical for accurate diagnosis, observation of disease progression and therapeutic response for patients with hypertrophic cardiomyopathy (HCM). The first cardiac myosin ATPase inhibitor, mavacamten has recently been listed on the Pharmaceutic Benefit Scheme (PBS) in Australia. On the basis of the EXPLORER-HCM study and as part of the PBS requirements, protocolised imaging for baseline and regular serial follow-up are required for ongoing PBS approval due to the risk of inducing left ventricular dysfunction. Full echocardiograms are not required for surveillance nor are they time- or cost-effective. Therefore, we propose an abbreviated 15-minute protocol for use in this setting.