How Does EGPA Affect the Heart? Why Screening Matters

If your main EGPA symptoms are asthma and sinus problems, you might wonder why your doctor ordered a cardiac MRI or an echocardiogram. The reason is that EGPA—a condition involving blood-vessel inflammation and high levels of white blood cells called eosinophils—can affect your heart even if you do not have chest pain or other obvious cardiac symptoms ^[1]. Because early detection is so important ^[2], screening with electrical tests, blood work, and imaging is a standard precaution to ensure your heart is healthy, establish a baseline (starting comparison) for your care, and catch any potential issues early ^[3].

Important Reassurance: Being sent for screening does not mean you definitely have heart involvement. For many patients, these tests are reassuring and provide a helpful starting point for your care team.

A Complete Heart Screening: What to Expect

Doctors use a combination of tests to get a complete picture of your heart’s health, as each test answers a different question ^[4]. Your specific testing plan depends on your symptoms, local practices, and early test results ^[1].

Here is how the tests complement each other:

• Electrocardiogram (ECG): A quick, painless test that measures the electrical activity of your heart to check for rhythm problems.
• Blood Biomarkers: Blood tests that measure specific proteins, like troponin (a marker of heart muscle injury) or BNP/NT-proBNP (markers of heart stress) ^[5].
• Echocardiogram: An ultrasound that shows how well your heart muscle is pumping and how your valves are working ^[1].
• Cardiac MRI (CMR): A highly detailed scan that can spot subtle signs of active inflammation, swelling (edema), or early scarring ^[6]. Doctors often order a CMR if they need more detail than an echocardiogram provides, or as a baseline test, because it can reveal abnormalities that other tests might miss ^[7].

Practical Details of a Cardiac MRI

A cardiac MRI uses a strong magnet, not radiation. It typically involves lying still in a scanner for 45 to 90 minutes while it makes loud tapping noises. You may also receive an IV contrast dye called gadolinium to help highlight inflammation or scarring ^[3].

Safety Note: Before the MRI, tell the imaging team if you have any implanted medical devices, metal in your body, claustrophobia, a history of kidney disease, or if you are pregnant, as these can affect whether the scan and the contrast dye are right for you.

How EGPA Can Affect the Heart

In EGPA, elevated levels of eosinophils can travel into different organs, where they release substances that cause inflammation and tissue injury ^[8]. When this happens in the heart muscle, it causes a condition called eosinophilic myocarditis (inflammation of the heart muscle) ^[8].

While the risk depends on the severity of the condition and your treatment, potential heart-related complications can include:

• Muscle damage and weakness: Inflammation can injure heart cells, reducing the heart’s ability to pump blood effectively ^[9]. If severe, this can lead to heart failure (when the heart isn’t pumping as well as it should) ^[10].
• Scarring (Fibrosis): Prolonged inflammation can cause permanent scarring in the heart muscle, making it stiff ^[8].
• Rhythm issues: Damage to the heart muscle can disrupt the electrical signals that control your heartbeat, leading to arrhythmias (irregular heartbeats) ^[4].
• Blood clots: While uncommon, inflammation in the inner lining of the heart can sometimes promote the formation of blood clots, which carry a risk of breaking loose and causing a stroke ^[11].

You might think that if you don’t have chest pain, shortness of breath, or palpitations, your heart is fine. However, some studies have found a substantial proportion of EGPA patients with heart involvement have no cardiac symptoms at all ^[1]. This is why screening is so essential.

What Happens if Something Is Found?

If your tests show signs of inflammation or other heart involvement, your care team will likely adjust your treatment plan based on whether the findings represent active inflammation or older scarring ^[4]. If active cardiac disease is confirmed, this may involve starting urgent anti-inflammatory or immunosuppressive medications to control the EGPA and protect your heart ^[12]. You will also likely be referred to a cardiologist to help manage your ongoing care.

A normal scan is reassuring, but because EGPA can change over time, your doctor will still monitor you at regular visits. Since asthma-related breathlessness and EGPA-related heart symptoms can overlap, do not dismiss new or changing symptoms as “just asthma.”

Urgent Cardiac Symptoms: Seek immediate emergency medical care if you experience new or worsening breathlessness at rest, chest pain or pressure, fainting, a sustained rapid or irregular heartbeat, sudden marked swelling in your legs, or stroke symptoms (like sudden weakness or confusion). Do not wait for your next scheduled appointment.