What is the treatment for myocardial bridge?

Treatment of Myocardial Bridging

Beta-blockers are the first-line treatment for symptomatic myocardial bridging, with calcium channel blockers as an alternative when beta-blockers are contraindicated or not tolerated. 1

Diagnosis and Assessment

Myocardial bridging occurs when a segment of a coronary artery runs intramurally through the myocardium, causing systolic compression of the vessel. Proper diagnosis is essential before initiating treatment:

• Gold standard diagnosis: Coronary angiography showing characteristic "milking effect" or systolic narrowing of the coronary artery 1
• Functional assessment: For symptomatic patients, evaluate hemodynamic significance using:
  • ECG exercise test
  • Dobutamine stress echocardiography
  • Myocardial perfusion scintigraphy
  • Intracoronary Doppler flow velocity measurements 1

Treatment Algorithm

1. Medical Therapy (First-Line)

• Beta-blockers: First choice for symptomatic patients 1, 2

  • Mechanism: Reduce heart rate, prolong diastole, decrease contractility
  • Target: Resting heart rate of 55-60 beats per minute 3
  • Evidence: Meta-regression shows patients treated with beta-blockers are more likely to remain free from angina (B -0.6, P = 0.013) 2

• Calcium channel blockers: Alternative when beta-blockers are contraindicated or not tolerated 1

  • Particularly effective for patients with vasospastic component

• Important caution: Nitrates are contraindicated as they can increase the angiographic systolic narrowing and worsen symptoms 1, 4

2. Invasive Treatment (For Medical Therapy Non-Responders)

For patients who remain symptomatic despite optimal medical therapy:

• Surgical options:

  • Myotomy (surgical unroofing of the bridge)
  • Coronary artery bypass grafting (CABG)
  • Evidence: Higher freedom from angina rate [84.5% (78.4-90.7; 95% CI)] compared to stenting 2

• Percutaneous coronary intervention (PCI) with stenting:

  • Less favorable outcomes than surgery
  • Higher incidence of major cardiovascular events related to target vessel revascularization [40.07% (19.83-60.32; 95% CI)] 2
  • Should be considered only in selected cases when surgery is not an option

Monitoring and Follow-up

• Regular clinical follow-up to assess symptom control
• Consider repeat functional testing if symptoms worsen or change in character 1
• For patients who underwent interventional procedures, follow standard post-PCI monitoring protocols

Special Considerations

• Athletes: Asymptomatic athletes with incidental myocardial bridging can participate in competitive sports; symptomatic athletes should be assessed for inducible myocardial ischemia before sports participation 1

• High-risk features requiring more aggressive management:

  • Deep bridges
  • Long tunneled segments
  • Evidence of myocardial ischemia on functional testing
  • Association with hypertrophic cardiomyopathy 1

Prognosis

Despite symptoms, patients with isolated myocardial bridging generally have a good long-term prognosis. After a median follow-up of 31 months, major cardiovascular events occurred in only 3.4% of patients, and 78.7% of conservatively managed patients remained free of symptoms 2.

Medical therapy alone, especially with beta-blockers, is sufficient to improve angina in most cases, making it the cornerstone of treatment for myocardial bridging.