Do patients with Becker muscular dystrophy require antihypertensive medication?

Blood Pressure Management in Patients with Becker Muscular Dystrophy

Patients with Becker muscular dystrophy should receive antihypertensive medication, particularly angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs), when they develop cardiac involvement, even before overt hypertension or heart failure symptoms appear. 1

Rationale for Blood Pressure Management in BMD

Becker muscular dystrophy (BMD) is an X-linked recessive disorder characterized by progressive muscle weakness that frequently involves cardiac muscle, leading to cardiomyopathy. Cardiomyopathy represents the number one cause of death in these patients 2. The cardiac involvement in BMD requires proactive management to prevent progression to heart failure.

Key considerations:

• BMD patients have a high risk of developing cardiomyopathy that can progress to heart failure
• Early intervention with RAAS blockers (ACEIs/ARBs) has been shown to improve cardiac outcomes
• Blood pressure targets should follow heart failure guidelines rather than standard hypertension guidelines

Evidence-Based Treatment Approach

First-Line Therapy:

• ACEIs or ARBs: Should be initiated early, even when LVEF is between 40-49% (not waiting until LVEF falls below 40%)
  • Research shows significantly better outcomes with early ACEi treatment in BMD patients 1
  • Early treatment reduced hospitalizations for heart failure (3.9% vs 11.8%) and prevented LVEF decline below 35% (17.6% vs 29.4%) 1

Blood Pressure Targets:

• Target systolic BP of 130 mmHg and lower if tolerated, but not below 120 mmHg 3
• Target diastolic BP below 80 mmHg, but not below 70 mmHg 3
• For older patients (≥65 years), target systolic BP range of 130-139 mmHg 3

Additional Medication Considerations:

• Beta-blockers: Consider adding for patients with reduced ejection fraction or heart failure symptoms
• Mineralocorticoid receptor antagonists (MRAs): Add for patients with progressive heart failure symptoms
• SGLT2 inhibitors: Consider for patients who develop heart failure with reduced ejection fraction

Monitoring and Follow-up

1. Regular cardiac evaluation with echocardiography to assess for cardiomyopathy development
2. Monitor blood pressure at each clinical visit
3. Check renal function and electrolytes 1-2 weeks after initiation or dose changes of RAAS inhibitors
4. Adjust medication doses based on blood pressure response and tolerability

Important Cautions

• Avoid NSAIDs: These medications can worsen heart failure in BMD patients with cardiac involvement 4
• Monitor for hypotension: BMD patients may have autonomic dysfunction
• Careful diuretic use: Excessive diuresis can lead to hypotension and renal dysfunction
• Corticosteroid consideration: In refractory heart failure cases, corticosteroid therapy might be beneficial 5

Algorithm for BP Management in BMD

1. Initial evaluation: Assess for cardiac involvement with echocardiography
2. If LVEF ≥50%: Consider prophylactic ACEI/ARB therapy
3. If LVEF 40-49%: Start ACEI/ARB therapy (early intervention) 1
4. If LVEF <40%: Start ACEI/ARB + beta-blocker + consider MRA
5. If heart failure symptoms develop: Optimize GDMT (Guideline-Directed Medical Therapy) including SGLT2 inhibitors
6. For all stages: Target BP <130/80 mmHg if tolerated 3

By implementing this proactive approach to blood pressure management in BMD patients, clinicians can significantly improve morbidity, mortality, and quality of life outcomes by preventing or delaying the progression of cardiomyopathy to end-stage heart failure.