What is the treatment for hypertrophic cardiomyopathy?

Treatment of Hypertrophic Cardiomyopathy

Beta blockers are the first-line pharmacologic treatment for symptomatic hypertrophic cardiomyopathy (HCM) patients, with a goal of achieving a resting heart rate of less than 60-65 bpm to reduce symptoms of angina, dyspnea, and palpitations. 1, 2

Pharmacologic Management

First-Line Therapy

• Beta blockers should be titrated to maximum tolerated doses within recommended ranges to achieve optimal symptom control 1, 2
• Beta blockers work through negative inotropic effects and by attenuating adrenergic-induced tachycardia, which prolongs diastolic filling period 3
• The reduction in heart rate allows for more efficient inactivation of myocardial contractile proteins, thereby improving diastolic filling 3

Second-Line Therapy

• Non-dihydropyridine calcium channel blockers, particularly verapamil, are recommended for patients who:
  • Do not respond to beta blockers
  • Have side effects from beta blockers
  • Have contraindications to beta blockers 1, 2
• Verapamil should be started at low doses and titrated up to 480 mg/day as needed 1, 2
• Verapamil must be used with extreme caution in patients with:
  • Severe outflow tract obstruction
  • Elevated pulmonary artery wedge pressure
  • Low systemic blood pressure
  • Severe dyspnea at rest 3, 4
• Dihydropyridine calcium channel blockers (e.g., nifedipine) should be avoided in patients with obstructive HCM as they may worsen symptoms due to vasodilatory effects 3, 1

Additional Pharmacologic Options

• For patients with obstructive HCM who remain symptomatic despite beta blockers and calcium channel blockers:
  • Disopyramide may be added in combination with a beta blocker or verapamil at doses of 400-600 mg/day 3, 1
  • Disopyramide should not be used alone in patients with atrial fibrillation as it may enhance atrioventricular conduction 1, 2
• Diuretics may be used cautiously for symptomatic relief in patients with pulmonary congestion, but should be used judiciously in those with outflow tract obstruction 3

Invasive Therapies for Refractory Cases

• Septal reduction therapy should be considered for severely symptomatic patients despite optimal medical therapy 3, 1
• Surgical septal myectomy is the preferred treatment for most eligible patients with severe symptoms and left ventricular outflow tract (LVOT) obstruction 1, 2
  • Should be performed at experienced centers with cumulative case volumes of at least 50 procedures
  • Particularly beneficial for younger patients, those with greater septal thickness, and those with concomitant cardiac disease requiring surgery 3, 2
• Alcohol septal ablation is an alternative for patients when:
  • Surgery is contraindicated
  • Surgical risk is unacceptable due to advanced age or significant comorbidities 1, 2

Special Considerations

• Anticoagulation is recommended for patients with atrial fibrillation and HCM, regardless of CHA₂DS₂-VASc score 1
• Avoid vasodilators (ACE inhibitors, ARBs) in obstructive HCM as they may worsen symptoms 1
• Low-intensity aerobic exercise is reasonable as part of a healthy lifestyle for HCM patients 1
• In asymptomatic patients, hydration and avoidance of environmental situations where vasodilatation may occur are important, especially in those with resting or provocable LVOT obstruction 3

Important Pitfalls to Avoid

• Septal reduction therapy should not be performed in asymptomatic patients with normal exercise capacity, regardless of gradient severity 1
• Combining beta blockers with verapamil or diltiazem should be done with caution due to potential for high-grade atrioventricular block 3
• Verapamil can cause serious adverse effects in patients with hypertrophic cardiomyopathy, including pulmonary edema and severe hypotension, particularly in those with high gradients or advanced heart failure 4
• When using disopyramide, monitor QTc interval during dose up-titration and reduce dose if it exceeds 480 ms 1

With optimal management, HCM has a low disease-related mortality rate of less than 1% per year 5, 6, transforming it into a treatable cardiovascular disease with extended longevity for most patients.