There are two main forms of HCM: obstructive HCM and non-obstructive HCM. In approximately two-thirds of HCM patients, the path followed by blood exiting the heart, known as the left ventricular outflow tract, or LVOT, becomes obstructed by the enlarged and diseased muscle, restricting the flow of blood from the heart to the rest of the body. Obstructive HCM patients, are at an increased risk of severe heart failure and death.
Symptomatic, non-obstructive HCM patients represent a distinct subgroup that is particularly lacking in available medical treatment options. People with non-obstructive HCM are typically diagnosed when their disease is more advanced than obstructive HCM patients.
Current treatment options for HCM are limited and no therapeutics targeted toward the underlying cause of the disease have been approved. Beta and calcium channel blockers, typically used to address heart failure, may provide some symptom relief in some patients, though there has not been any clinical research directly supporting the use of these drugs in HCM. For a subset of HCM patients with more advanced disease progression or more pronounced symptoms, surgical or other invasive interventions may be appropriate, including heart transplantation, use of an implantable cadioverter-defibrillator, open heart surgical myectomy or percutaneous alcohol septal ablation.