Is an echocardiogram (echo) necessary for stroke diagnosis if a Magnetic Resonance Imaging (MRI) scan is still pending?

From the Guidelines

Yes, an echocardiogram (echo) is often recommended for stroke patients even if MRI results are still pending, as it can provide critical information about potential cardiac sources of emboli, which account for approximately 20% of ischemic strokes 1. The echo can detect conditions like patent foramen ovale, atrial septal defects, valvular disease, left ventricular thrombi, or atrial fibrillation-related atrial appendage thrombi that may have caused the stroke. This information is valuable for determining stroke etiology and guiding secondary prevention strategies, independent of MRI findings which primarily assess brain tissue damage.

According to the 2021 guideline for the prevention of stroke in patients with stroke and transient ischemic attack, a diagnostic evaluation is recommended for gaining insights into the etiology of and planning optimal strategies for preventing recurrent stroke, with testing completed or underway within 48 hours of onset of stroke symptoms 1. Additionally, the guideline recommends that in patients with cryptogenic stroke, echocardiography with or without contrast is reasonable to evaluate for possible cardiac sources of or transcardiac pathways for cerebral embolism 1.

Some key points to consider when deciding whether to perform an echo in a stroke patient with pending MRI results include:

• The potential for the echo to provide information about cardiac sources of emboli that may not be apparent on MRI
• The importance of determining stroke etiology in guiding secondary prevention strategies
• The recommendation for echocardiography in patients with cryptogenic stroke or suspected cardioembolic mechanism
• The use of transthoracic echocardiography (TTE) as the initial imaging modality, with transesophageal echocardiography (TEE) reserved for cases where higher resolution imaging is needed or when TTE results are inconclusive.

Overall, obtaining an echo early in the stroke workup can expedite treatment decisions and potentially prevent recurrent strokes, making it an important component of comprehensive stroke care that should not be delayed while waiting for MRI results 1.

From the Research

Echocardiography for Stroke Diagnosis

• Echocardiography is a diagnostic tool used to assess the heart's structure and function, and it can help identify potential causes of stroke, such as atrial fibrillation or valvular heart disease 2.
• However, the need for echocardiography in stroke diagnosis is not universally agreed upon, and its use may depend on individual patient circumstances and the availability of other diagnostic tools, such as MRI 3.

Relationship Between Echocardiography and MRI

• MRI is a non-invasive imaging technique that can provide detailed images of the brain and blood vessels, and it is often used to diagnose and manage stroke patients 4.
• While echocardiography can provide valuable information about the heart's structure and function, it may not be necessary for stroke diagnosis if MRI is available and pending 3.
• However, echocardiography may still be useful in certain situations, such as when MRI is contraindicated or when additional information about the heart's structure and function is needed 2.

Clinical Guidelines and Recommendations

• Clinical guidelines and recommendations for the use of echocardiography in stroke diagnosis vary depending on the patient's individual circumstances and the availability of other diagnostic tools 5, 2.
• The American Heart Association and other professional organizations recommend the use of echocardiography in certain situations, such as when atrial fibrillation or valvular heart disease is suspected 2.
• However, the decision to use echocardiography should be made on a case-by-case basis, taking into account the patient's individual needs and circumstances 5, 2.

Anticoagulation Therapy

• Anticoagulation therapy is an important aspect of stroke prevention and management, particularly in patients with atrial fibrillation or valvular heart disease 6, 2.
• The choice of anticoagulant therapy depends on individual patient circumstances, including the presence of valvular heart disease, kidney function, and bleeding risk 5, 2.
• Direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs) are commonly used anticoagulants, and the choice between them depends on individual patient circumstances and clinical guidelines 6, 5, 2.