What are the treatment options for hypertrophic obstructive cardiomyopathy (HOCM) with mitral regurgitation?

From the Guidelines

Treatment for hypertrophic obstructive cardiomyopathy (HOCM) with mitral regurgitation should begin with medications, including cardiac myosin inhibitors such as mavacamten, to reduce symptoms and prevent complications, as recommended by the 2024 guideline 1. The primary goal of treatment is to alleviate symptoms, prevent complications, and improve quality of life.

• First-line medications include beta-blockers (such as metoprolol 25-100 mg twice daily or bisoprolol 2.5-10 mg daily) to decrease heart rate and contractility, reducing outflow obstruction, as supported by the 2011 ACCF/AHA guideline 1.
• Non-dihydropyridine calcium channel blockers (verapamil 120-480 mg daily or diltiazem 120-540 mg daily) may be used if beta-blockers are not tolerated, as suggested by the 2011 ACCF/AHA guideline 1.
• Disopyramide (100-300 mg every 6-12 hours) can be added for persistent symptoms, as recommended by the 2003 ACC/ESC clinical expert consensus document 1. For patients with severe symptoms despite optimal medical therapy, invasive options include septal reduction procedures such as surgical myectomy (removing part of the thickened septum) or alcohol septal ablation (creating a controlled infarct in the septum), with surgical myectomy being the preferred treatment for most patients, as stated in the 2011 ACCF/AHA guideline 1. It is essential to select patients carefully for invasive therapies, considering factors such as symptoms, anatomic and hemodynamic criteria, and the presence of concomitant cardiac disease, as emphasized in the 2011 ACCF/AHA guideline 1. Patients should avoid dehydration, excessive alcohol, and strenuous exercise, particularly activities involving sudden bursts of exertion or Valsalva maneuvers, as these can worsen obstruction and symptoms.

From the FDA Drug Label

In 120 patients with hypertrophic cardiomyopathy (most of them refractory or intolerant to propranolol) who received therapy with verapamil at doses up to 720 mg/day, a variety of serious adverse effects were seen Three patients died in pulmonary edema; all had severe left ventricular outflow obstruction and a past history of left ventricular dysfunction. Eight other patients had pulmonary edema and/or severe hypotension; abnormally high (greater than 20 mmHg) pulmonary wedge pressure and a marked left ventricular outflow obstruction were present in most of these patients

The treatment options for Hypertrophic Obstructive Cardiomyopathy (HOCM) with mitral regurgitation are not directly addressed in the provided drug labels.

• Verapamil may be used in patients with HOCM, but it is essential to carefully evaluate the patient's condition and potential risks, such as pulmonary edema and severe hypotension.
• The use of verapamil in patients with HOCM and mitral regurgitation should be approached with caution, and the patient should be closely monitored for potential adverse effects 2.
• It is crucial to consider the patient's overall clinical situation and to consult with a specialist before initiating treatment with verapamil or any other medication for HOCM with mitral regurgitation 2.

From the Research

Treatment Options for Hypertrophic Obstructive Cardiomyopathy (HOCM) with Mitral Regurgitation

• Medical therapy is the initial treatment for symptomatic patients with HOCM, using medications such as beta blockers, calcium channel blockers, and disopyramide to decrease obstructive gradients and symptoms 3, 4, 5.
• For patients with severe obstruction or symptoms refractory to medical therapy, invasive treatment options are available, including surgical correction of the left ventricular outflow tract (LVOT) obstruction or percutaneous alcohol septal ablation 3, 6, 5.
• Surgical myectomy is a highly effective treatment for HOCM, with a >90% relief of obstruction and improvement in symptoms, and a perioperative mortality rate of <1% 6.
• Alcohol septal ablation is a less invasive treatment option, with comparable hemodynamic and clinical results to septal myectomy in many patients, but with some limitations, such as dependence on the septal perforator artery supplying the area of contact between the hypertrophied septum and the anterior leaflet of the mitral valve 6, 5.
• Extended septal myectomy can be combined with anterior mitral leaflet plication or mitral valve replacement to correct mitral regurgitation and abolish systolic anterior motion, resulting in significant reduction in LVOTG, grade of mitral regurgitation, and systolic anterior motion, and improvement in functional class 7.

Invasive Treatment Options

• Surgical myectomy: a surgical procedure that involves removing a portion of the thickened septal wall to relieve LVOT obstruction 6, 7.
• Alcohol septal ablation: a percutaneous procedure that involves injecting alcohol into the septal perforator artery to reduce the thickness of the septal wall and relieve LVOT obstruction 6, 5.
• Dual chamber sequential pacing: a treatment option that involves implanting a pacemaker to reduce the risk of sudden death and symptomatology in selected patients 4.

Considerations for Treatment

• Patient preference and the availability and experience of the operator and institution at which the patient is being treated are important factors in deciding which treatment option to choose 6.
• The presence of mitral regurgitation and the need for correction of this condition should be taken into account when selecting a treatment option 4, 7.