What can be done when coronary artery disease progresses in patients with Duchenne muscular dystrophy?

Management of Coronary Artery Disease Progression in Duchenne Muscular Dystrophy

When coronary artery disease progresses in patients with Duchenne muscular dystrophy (DMD), a combination of ACE inhibitors, beta-blockers, and mineralocorticoid receptor antagonists should be implemented as the primary pharmacological intervention strategy.

Pharmacological Management

First-Line Medications

• ACE inhibitors (such as perindopril or lisinopril) should be started by age 10 or earlier, even in asymptomatic patients, as they slow the decline in cardiac function and reduce the risk of progressive cardiac complications 1
• Beta-blockers should be added to the regimen, particularly when there is evidence of ventricular dysfunction or elevated heart rate 1
• Mineralocorticoid receptor antagonists (such as eplerenone) have shown benefit in attenuating the decline in left ventricular function and should be considered as part of the combination therapy 1

Medication Considerations

• The timing of medication initiation is critical - earlier intervention (before onset of cardiac symptoms) has shown better outcomes 1
• Careful titration of medications is necessary as DMD patients typically have lower baseline blood pressure, which can complicate standard heart failure medication dosing 1
• Glucocorticoids (prednisone/prednisolone), while beneficial for skeletal muscle function, may have negative impacts on cardiac pathology and should be carefully monitored when used concurrently with cardiac medications 1, 2

Cardiac Surveillance and Monitoring

Imaging Recommendations

• Cardiac Magnetic Resonance Imaging (CMR) is preferred over echocardiography for assessing cardiac status due to superior information on tissue characteristics, chamber dimensions, and function 1
• Specific CMR measurements to monitor include:
  • Degree and pattern of late gadolinium enhancement
  • Myocardial strain
  • Extracellular volume 1
• Regular cardiac monitoring schedule:
  • Echocardiogram at diagnosis or by age 6 years
  • Maximum 24 months between investigations until age 10 years
  • Annual evaluations thereafter 1

Arrhythmia Management

• Regular screening for arrhythmias is essential as they are a potential contributor to mortality in DMD 1
• In advanced DMD cardiomyopathy with ejection fraction <35%, consider following adult heart failure guidelines for primary arrhythmia prevention 1
• For patients with atrial fibrillation/flutter or ventricular arrhythmias, standard heart failure antiarrhythmic management should be followed 1

Advanced Interventions

For Severe Progression

• Implantable cardioverter-defibrillators (ICDs) may be considered for patients with severe ventricular dysfunction (EF <35%), though risks may be higher in DMD patients due to skeletal muscle and respiratory compromise 1
• Mechanical circulatory support with ventricular assist devices has been described in case reports and may be considered as a bridge to transplantation or destination therapy 1
• Biventricular pacing (cardiac resynchronization therapy) may be considered, though the pattern of inferolateral involvement in DMD hearts may limit response 1

Respiratory Considerations

• Earlier institution of nocturnal non-invasive ventilation may have cardiac benefits and should be considered as disease progresses 1
• The concurrent decline in respiratory and cardiac function may be interdependent, requiring coordinated management of both systems 1

Clinical Pitfalls and Caveats

• Standard heart failure symptoms like exercise limitation or dyspnea are often absent in DMD due to skeletal muscle limitations, requiring unique assessment approaches 1
• Severe kyphoscoliosis and respiratory muscle weakness increase risks associated with invasive cardiac procedures 1
• End-of-life management preferences should be discussed early in the disease course, before urgent interventions are needed 1
• Female carriers of DMD mutations may also develop cardiac complications and should be monitored with CMR 1, 3

Multidisciplinary Approach

• Coordination between cardiology, neurology, pulmonology, and rehabilitation medicine is essential for comprehensive management 1
• Regular clinic appointments should occur every 6 months with appropriate specialist assessments 1
• Long-term patient/family/physician relationships facilitate better understanding of goals of therapy and decision-making for advanced interventions 1