What is the recommended treatment for myocardial bridging?

Treatment of Myocardial Bridging

Beta-blockers are the first-line treatment for symptomatic myocardial bridging, with surgery (myotomy) or coronary bypass considered for patients with refractory symptoms. 1, 2

Pathophysiology and Clinical Significance

Myocardial bridging occurs when a segment of a major epicardial coronary artery (most commonly the left anterior descending artery) runs intramurally through the myocardium, causing systolic compression of the vessel 1, 3. While often asymptomatic and considered benign in most cases, myocardial bridging can cause:

• Myocardial ischemia and angina 1, 4
• Myocardial infarction 1, 5
• Ventricular arrhythmias 1
• Atrioventricular block 1
• Sudden cardiac death (rarely) 1, 3

Diagnostic Evaluation

For symptomatic patients with suspected myocardial bridging, evaluation should include:

• ECG exercise testing or stress echocardiography to assess for inducible ischemia 1
• Myocardial perfusion scintigraphy to evaluate for ischemia 1
• Coronary angiography to visualize systolic compression 1
• In selected cases, intracoronary Doppler flow velocity measurement to assess functional significance 1, 4

Treatment Algorithm

First-Line Treatment: Medical Therapy

• Beta-blockers are the mainstay of treatment and should be used as first-line therapy 1, 2, 4

  • Beta-blockers reduce heart rate, prolong diastole, and decrease contractility, improving coronary flow 2, 4
  • Meta-regression analysis shows patients treated with beta-blockers are more likely to remain free from angina 2

• Non-dihydropyridine calcium channel blockers can be considered as an alternative when beta-blockers are contraindicated 4

• AVOID nitrates as they can worsen symptoms by increasing the angiographic systolic narrowing 1, 4

Second-Line Treatment: Invasive Management

For patients with refractory symptoms despite optimal medical therapy, consider:

1. Surgical myotomy or coronary artery bypass grafting (CABG) 1, 2

   • Surgical treatment appears more effective than stenting for symptom relief 2
   • Freedom from angina is higher with surgery (84.5%) compared to stenting (54.7%) 2

2. Stenting 1, 2

   • Consider only when medical and surgical options are not feasible
   • Associated with higher rates of target vessel revascularization (40.07%) 2
   • After stent placement, patients should be restricted to low-intensity activities for 6 months 1

Special Considerations

• In patients with myocardial bridging and evidence of myocardial ischemia, it is reasonable to restrict participation in competitive sports with high dynamic and static demands 1

• After surgical repair, resumption of full activities can proceed after complete healing and testing showing no evidence of myocardial ischemia 1

• Long-term prognosis for patients with isolated myocardial bridging is generally good, with major cardiovascular events occurring in only 3.4% of patients over a median follow-up of 31 months 2

Monitoring and Follow-up

• Patients should undergo periodic reassessment with stress testing to evaluate for residual ischemia 1

• For athletes with myocardial bridging who have undergone surgical repair, resumption of competitive sports can be considered after:

  • Complete sternal healing
  • Testing showing no evidence of myocardial ischemia
  • No complex ventricular arrhythmias 1

Pitfalls to Avoid

• Do not prescribe nitrates as they can worsen symptoms by increasing systolic compression 1, 4
• Do not underestimate the clinical significance of myocardial bridging in symptomatic patients, especially those with evidence of ischemia 1, 5
• Avoid stenting as first-line invasive therapy due to high rates of restenosis and target vessel revascularization 2