Cardiac PYP Scan

What is a cardiac PYP scan?

A cardiac PYP scan is a nuclear imaging test to diagnose transthyretin amyloidosis (ATTR) that affects your heart.

“PYP” stands for the type of radioactive tracer the test uses: technetium 99m pyrophosphate. Some healthcare providers may call it a pyrophosphate scan. The tracer is a small amount of radioactive material. Providers may now mainly use technetium 99m hydroxymethylene diphosphonate, or HDMP. But based on the past name, they still call it a PYP scan.

A PYP scan is one of the last steps to get an official ATTR diagnosis. This test is helpful because it can make the diagnosis of ATTR and differentiate it from AL amyloidosis. These are both types of cardiac amyloidosis. And they have different treatments.

Before scientists discovered this scan, a heart biopsy was necessary to distinguish between ATTR and AL amyloidosis. A PYP scan is much less invasive.

How does the test work?

During a cardiac PYP scan, a healthcare provider injects a small amount of radiotracer into a vein in your arm. They use a SPECT-CT machine to take images of your body with extra focus on your heart. The gamma camera in a SPECT-CT shows the areas of your body where the radiotracer builds up. It collects in areas of your heart if you have ATTR.

How do I prepare for a cardiac PYP scan?

You don’t need to do anything special to prepare for a PYP scan. You should leave your jewelry and valuables at home. A healthcare provider may tell you to wear comfortable clothes without metal and remove metal items from your pockets. Metal may interfere with the scan.

For your own comfort, you may want to pee before the scan.

What to expect during a PYP scan

A cardiac PYP scan itself takes about 45 minutes. But you may need to be at the facility for three or four hours for the entire process.

In general, you can expect the following during a PYP scan:

1. A healthcare provider places an IV in your arm and injects the radiotracer.
2. You wait about three hours to let the tracer move through your body.
3. When it’s time for the imaging, you lie on your back on the scanner bed. You may need to raise your arms above your head. A provider will guide you.
4. The scanner moves around your body but doesn’t touch you. You need to lie still while it takes pictures of your whole body, with special focus on your chest.

What are the side effects of a PYP scan?

In general, a cardiac PYP scan is a low-risk test. It involves a low level of radiation.

What can I expect after a PYP scan?

You can get back to your normal routine (like working, eating or driving) right away after a PYP scan.

What type of results do you get and what do they mean?

It may take a few days to get the results of your PYP scan. Ask your provider what time frame you can expect.

Based on how much of the radiotracer collects in your heart muscle after the cardiac PYP scan, you’ll get a positive or negative result. Positive means you have ATTR. Negative means you don’t.

Your provider may also talk about a “grade” from the scan, which compares how much tracer shows in your heart versus your ribs:

• Grade 0: Negative
• Grade 1: Unclear
• Grades 2 and 3: Positive for ATTR amyloidosis

How accurate is a PYP scan?

A cardiac PYP scan is very accurate for diagnosing transthyretin amyloid cardiomyopathy (ATTR-CM). It’s the standard test for diagnosing this condition. But you may have several other tests before this scan to rule out more common causes of your symptoms.

If the results are abnormal, what are the next steps?

Once your healthcare provider makes a diagnosis, they’ll offer a treatment plan. Treatments vary based on the type of amyloidosis.