What is the management difference between obstructive and non-obstructive Hypertrophic Obstructive Cardiomyopathy (HOCM)?

From the Guidelines

The management of obstructive Hypertrophic Obstructive Cardiomyopathy (HOCM) differs significantly from non-obstructive HOCM, with obstructive HOCM requiring interventions aimed at reducing outflow tract obstruction, whereas non-obstructive HOCM focuses on controlling symptoms and preventing complications. The primary goal in managing obstructive HOCM is to reduce the left ventricular outflow tract obstruction, which can be achieved through medications such as beta-blockers (e.g., metoprolol 25-200 mg twice daily or bisoprolol 2.5-10 mg daily) and non-dihydropyridine calcium channel blockers (e.g., verapamil 120-480 mg daily) 1. In contrast, non-obstructive HOCM management primarily involves the use of beta-blockers or calcium channel blockers to control symptoms and prevent complications, without the need for disopyramide. For obstructive cases with severe symptoms despite medical therapy, invasive options such as surgical myectomy or alcohol septal ablation may be considered to physically reduce the obstruction 1. Key considerations in the management of both obstructive and non-obstructive HOCM include:

• The use of beta-blockers as first-line agents for symptomatic patients
• The potential need for invasive interventions in obstructive HOCM
• The importance of arrhythmia management, including anticoagulation and consideration of implantable cardioverter-defibrillators for high-risk patients
• The need for individualized treatment approaches based on patient-specific factors, such as symptom severity and underlying pathophysiology. In terms of specific medications, beta-blockers and non-dihydropyridine calcium channel blockers are recommended as first-line agents for both obstructive and non-obstructive HOCM, with the goal of reducing symptoms and preventing complications 1. Overall, the management of HOCM requires a comprehensive approach that takes into account the underlying pathophysiology, symptom severity, and individual patient factors, with the goal of reducing morbidity, mortality, and improving quality of life.

From the Research

Management of HOCM

The management of Hypertrophic Obstructive Cardiomyopathy (HOCM) differs between obstructive and non-obstructive types.

• For patients with obstructive HOCM, the management includes:
  • Medical therapy with beta blockers, disopyramide, or verapamil to control symptoms and reduce the obstructive gradient 2, 3
  • Septal reduction therapy, either surgical septal myectomy or alcohol septal ablation, for patients with severe symptoms unresponsive to medical therapy 2, 4, 5, 6
• For patients with non-obstructive HOCM, the management is focused on:
  • Treatment of heart failure with preserved ejection fraction (HFpEF) 3
  • Prevention of sudden cardiac death with implantable cardioverter-defibrillator (ICD) for high-risk patients 2

Septal Reduction Therapy

Septal reduction therapy is a treatment option for patients with obstructive HOCM who have severe symptoms despite optimal medical therapy.

• Surgical septal myectomy is a highly effective procedure with a >90% relief of obstruction and improvement in symptoms, but it is more invasive 4
• Alcohol septal ablation is a less invasive procedure with comparable results to septal myectomy in many patients, but the results are dependent on the septal perforator artery supplying the area of the contact between the hypertrophied septum and the anterior leaflet of the mitral valve 4, 6

Patient Selection

The selection of patients for septal reduction therapy depends on various factors, including:

• Severity of symptoms and obstructive gradient
• Patient preference
• Availability and experience of the operator and institution
• Presence of comorbidities 2, 4