From the Guidelines
The primary treatment for Hypertrophic Obstructive Cardiomyopathy (HOCM) is beta-blockers, which are generally considered the first-line agent for most patients with obstructive HCM, as they have been shown to reduce symptoms and improve quality of life 1. The initial approach typically involves medication and lifestyle modifications.
First-line Medications
- Beta-blockers (e.g., metoprolol 25-100 mg twice daily) to reduce heart rate and contractility, which should be titrated to a dose where symptom benefit is observed 1.
- Calcium channel blockers (e.g., verapamil 80-120 mg three times daily) if beta-blockers are not tolerated.
- Disopyramide (100-300 mg twice daily) may be added to reduce obstruction, but should be used in combination with another medication that has atrioventricular nodal blocking properties 2.
Lifestyle Modifications
- Avoiding dehydration and excessive alcohol consumption
- Moderate aerobic exercise, avoiding intense activities
- Maintaining a healthy weight For patients with severe symptoms or those not responding to medical therapy, invasive treatments may be considered: ### Invasive Treatments
- Septal myectomy: Surgical removal of part of the thickened septum
- Alcohol septal ablation: Injection of alcohol into the septal artery to induce controlled infarction
- Cardiac myosin inhibitors (e.g., mavacamten) may also be considered for adult patients who do not respond to first-line therapy, as they have been shown to improve LVOT gradients, symptoms, and functional capacity in 30% to 60% of patients with obstructive HCM 2. It's crucial to manage HOCM under the guidance of a cardiologist specializing in this condition, as treatment needs to be tailored to each patient's specific presentation and needs.
Additional Considerations
- Vasodilators (e.g., angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, dihydropyridine calcium channel blockers) or digoxin should be discontinued in patients with obstructive HCM, as they can worsen symptoms caused by dynamic outflow tract obstruction 3. Regular follow-ups and echocardiograms are essential to monitor disease progression and treatment efficacy.
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 Sinus bradycardia occurred in 11% of the patients, second-degree AV block in 4%, and sinus arrest in 2%.
The treatment for Hypertrophic Obstructive Cardiomyopathy (HOCM) may include verapamil, but it should be used with caution due to the risk of serious adverse effects, such as:
- Pulmonary edema
- Severe hypotension
- Sinus bradycardia
- Second-degree AV block
- Sinus arrest It is essential to carefully monitor patients and adjust the dosage as needed to minimize the risk of these adverse effects 4.
From the Research
Treatment Options for Hypertrophic Obstructive Cardiomyopathy (HOCM)
The treatment for HOCM encompasses several approaches, including:
- Activity restriction with avoidance of volume depletion
- Prevention of sudden cardiac death
- Control of symptoms
- Screening of relatives 5 Pharmacologic treatment of symptoms in patients with HOCM consists of:
- Negative inotropic drugs, namely beta blockers
- Disopyramide
- A nondihydropyridine calcium channel blocker (CCB), usually verapamil, may be used in patients with noncardiac side-effects of beta blockers 5
Septal Reduction Therapy
For patients with intolerable symptoms despite optimal conservative therapy, septal reduction therapy (SRT) should be considered and should be performed by experienced operators in institutions with multidisciplinary HCM programs 5. This includes:
- Surgical myectomy
- Alcohol septal ablation (ASA) Younger patients with extreme hypertrophy are usually offered septal myectomy, while older patients, and those with important comorbidities are usually directed to ASA 5
Invasive Treatment Approaches
Several invasive treatment approaches are available for HOCM, including:
- Alcohol septal ablation (ASA)
- Surgical myectomy (SM)
- Dual-chamber pacing
- Radiofrequency catheter ablation 6 The choice of treatment depends on various factors, including patient preference and the availability and experience of the operator and institution 7
Pharmacological and Non-Pharmacological Treatment
Pharmacological management remains an effective approach to the majority of patients with obstructive hypertrophic cardiomyopathy 8. However, a significant subset fails to improve sufficiently with medical therapy initially, or progressively becomes more symptomatic despite augmented medications over time. Non-pharmacologic management, particularly septal reduction therapy, has undergone iterative modifications that improve outcomes 8. Current guidelines support these therapies based on large observational studies, with choice of therapy based on a variety of factors but again based primarily on expert consensus opinion 8
Patient Selection and Treatment Algorithm
Patient selection for the procedure is crucial, and a balanced discussion with the patients of the benefits and risks of the procedures should be undertaken 5. Treatment algorithms can add in identification of patients who may benefit from advanced therapies, and should be instituted routinely to improve care for the majority of patients with symptomatic hypertrophic cardiomyopathy 8