Myectomy: A Cardiologist’s Perspective
The contemporary myectomy operation provides for virtually complete reconstruction of the LV chamber and outflow tract to ensure obliteration of subaortic obstruction, including extended resection of ventricular septum to the base of the papillary muscles, as well as reorientation of the mitral valve plane away from the septum by abolishing abnormal chordal connections and modifying abnormally positioned papillary muscles, and in some patients intervention on an elongated mitral valve leaflet to decrease length and leaflet mobility. Abnormalities can also be effectively treated at time of myectomy, including coronary artery bypass grafting, primary valvular repair, and Cox-maze procedure for atrial fibrillation.
When surgical myectomy is performed in high-volume dedicated hypertrophic cardiomyopathy (HCM) centers, subaortic gradients are abolished in more than 95 percent of patients. The more complete reduction in obstruction with myectomy translates to a long-term improvement in symptoms by one or more New York Heart Association (NYHA) class in more than 90 percent of patients, with most patients restored to a normal quality of life often without the requirement for continued drug treatment. Only about 5 percent of operated patients experience persistent functional limitation despite abolition of the gradient with myectomy, most commonly because of the presence of significant comorbidities, including obesity.
Over the last sixty years, myectomy has been the definitive treatment option for patients with symptomatic obstructive HCM given the opportunity with surgical intervention to permanently reverse heart failure symptoms in relatively young HCM patients with a one-time, low risk procedure. For these reasons, myectomy has been appropriately characterized as affording patients one of the most striking clinical benefits of any cardiovascular therapy.