What is the management of myocardial bridge (a congenital coronary artery anomaly)?

From the Guidelines

Management of myocardial bridges typically begins with conservative approaches for asymptomatic or mildly symptomatic patients, focusing on beta-blockers as first-line therapy, as recommended by the most recent guidelines 1. The goal of treatment is to reduce morbidity, mortality, and improve quality of life by alleviating symptoms and preventing complications such as myocardial ischemia, myocardial infarction, and sudden cardiac death.

Conservative Management

• Beta-blockers, such as metoprolol (25-200 mg daily) or atenolol (25-100 mg daily), are preferred as they reduce heart rate, contractility, and oxygen demand, allowing more time for diastolic coronary filling 1.
• Non-dihydropyridine calcium channel blockers like verapamil (120-360 mg daily) or diltiazem (120-360 mg daily) are effective alternatives for patients who cannot tolerate beta-blockers.
• Nitrates should be avoided as they can worsen symptoms by increasing contractility and reducing preload.

Invasive Management

• For patients with persistent symptoms despite optimal medical therapy, more invasive options include surgical myotomy (physically cutting the bridge) or coronary stenting, though stenting carries risks of in-stent restenosis and perforation 1.
• Surgical revascularization in centers with expertise in the surgical management of anomalous coronary arteries is suggested, particularly for patients with evidence of ischemia or ventricular dysfunction 1.

Lifestyle Modifications

• Lifestyle modifications are also important, including avoiding strenuous exercise that significantly increases heart rate.
• Regular follow-up with cardiac imaging is recommended to monitor for progression of symptoms or development of complications such as accelerated atherosclerosis proximal to the bridge.

Individualized Approach

• The management approach should be individualized based on symptom severity, anatomical characteristics of the bridge (depth and length), and presence of concomitant coronary artery disease, as highlighted in the 2020 AHA/ACC guideline for the diagnosis and treatment of patients with hypertrophic cardiomyopathy 1.
• Myocardial bridging, a congenital anomaly, may impair blood flow and is a rare cause of myocardial ischemia in a subset of patients, and its management should be tailored to the individual patient's needs 1.

From the Research

Management of Myocardial Bridge

The management of myocardial bridge, a congenital coronary artery anomaly, can be divided into medical therapy and surgical interventions.

• Medical therapy includes the use of beta blockers, calcium channel blockers, ivabradine, or a combination thereof 2, 3, 4, 5.
• Surgical interventions include deroofing the bridge and revascularisation of the affected region with bypass grafting 2, 3, 4, 5.
• The decision to undergo surgical management of myocardial bridging is difficult, as many of these patients are young and otherwise healthy, and long-term outcomes of surgical intervention should be considered carefully prior to pursuing surgical management 3.
• A combined approach of diagnosis, treatment, and follow-up is necessary to reduce the morbidity and mortality associated with this condition 6.
• Pharmacological treatment alone, especially with beta-blockers, is able to improve angina in most cases, and surgical treatment appears to be more effective than stenting in nonresponders 5.

Treatment Options

Treatment options for myocardial bridge mainly focus on relieving symptoms and preventing adverse outcomes.

• The use of pharmacological agents, such as beta blockers and calcium channel blockers, has been documented in numerous studies 2, 3, 4, 5.
• Surgical and percutaneous interventions, including coronary artery bypass grafting and stenting, have also been used to treat myocardial bridge 2, 3, 4, 5.
• The choice of treatment depends on the severity of symptoms and the presence of other underlying conditions 2, 3, 4, 5.

Diagnostic Methods

Several diagnostic methods have been proposed to diagnose myocardial bridge, including:

• Invasive modalities, such as intravascular ultrasound (IVUS) and coronary angiography, which offer high specificity and sensitivity 6.
• Non-invasive methods, such as Doppler ultrasound, multislice computed tomography (MSCT), and magnetic resonance imaging (MRI), which are advantageous due to their non-invasive nature, high sensitivity and specificity, and cost-effectiveness 6.