What is the best treatment approach for a 65-year-old male with apical HCM and apical aneurysm who develops new onset AF?

Management of New-Onset Atrial Fibrillation in Apical HCM with Apical Aneurysm

For a 65-year-old male with apical hypertrophic cardiomyopathy (HCM) and apical aneurysm who develops new onset atrial fibrillation (AF), a rhythm control strategy with amiodarone plus anticoagulation is the recommended approach due to the high risk of thromboembolism and poor tolerance of AF in HCM patients.

Risk Assessment and Initial Management

Thromboembolism Risk

• Patients with HCM and AF have a significantly elevated risk of stroke and thromboembolism
  • In a study of 480 patients with HCM, the odds ratio for stroke in those with AF was 17.7 1
  • AF is associated with increased mortality in HCM patients (3% in patients with AF versus 1% in sinus rhythm per year) 1
• The presence of an apical aneurysm further increases thromboembolic risk

Immediate Management

1. Assess hemodynamic stability:

   • If hemodynamically unstable: Immediate direct current cardioversion 1
   • If stable: Proceed with rate control while initiating anticoagulation

2. Initial rate control:

   • Use beta-blockers or non-dihydropyridine calcium channel blockers 1
   • Avoid digoxin as it may increase outflow gradient in HCM patients 1

Definitive Management Strategy

Anticoagulation

• Immediate anticoagulation is mandatory regardless of CHA₂DS₂-VASc score 1
• Options:
  • Vitamin K antagonist (warfarin) with target INR 2.0-3.0 1
  • Direct oral anticoagulants (DOACs) may be considered, though specific data in HCM patients are limited 1
• Anticoagulation should be lifelong, even if sinus rhythm is restored 1

Rhythm Control Strategy

• Rhythm control is preferred over rate control in HCM patients due to poor tolerance of AF 1
• Medication options:
  • First choice: Amiodarone (in combination with rate-controlling agents) 1
  • Alternative: Disopyramide (with ventricular rate-controlling agents) 1
• Sotalol may be considered but requires careful QT monitoring 2

Rate Control (if rhythm control is unsuccessful)

• Preferred agents:
  • Beta-blockers (e.g., metoprolol)
  • Non-dihydropyridine calcium channel blockers (diltiazem, verapamil)
  • Combination therapy may be necessary 1, 2
• Target heart rate: <100 BPM at rest 1

Catheter Ablation Considerations

• Consider if refractory to medical therapy 1
• Important caveats for this patient:
  • Presence of apical aneurysm is associated with higher recurrence rates after ablation 3
  • Very late AF relapses post-ablation are common in HCM patients 3
  • Higher procedural complication rates have been reported (9.3%) 3

Long-Term Monitoring and Follow-up

Monitoring

• Regular assessment of:
  • Heart rhythm and rate control
  • Anticoagulation efficacy and safety
  • Signs of heart failure
  • Thromboembolic events

Prognosis Considerations

• The combination of apical HCM with apical aneurysm and AF represents a high-risk phenotype
• Left ventricular apical aneurysm is an independent predictor of AF recurrence after ablation 3
• AF is associated with increased mortality in HCM patients, primarily due to heart failure 1

Special Considerations

ICD Evaluation

• Consider evaluation for ICD placement given the high-risk features:
  • Apical aneurysm increases risk of ventricular arrhythmias
  • AF in HCM is associated with increased mortality 1

Lifestyle Modifications

• Maintain optimal blood pressure control
• Regular moderate physical activity (avoiding high-intensity competitive sports) 1
• Avoid alcohol excess 1, 2

This approach prioritizes stroke prevention with anticoagulation while attempting to restore and maintain sinus rhythm with amiodarone, given the poor tolerance and increased mortality associated with AF in HCM patients, particularly those with apical aneurysms.