Cardiac PYP Scan: Testing for ATTR Cardiac Amyloidosis
Updated: 2 days ago
Written and medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: November 2026 · How we review
Quick Answer
A cardiac PYP scan, or pyrophosphate scan, is a noninvasive nuclear imaging test that shows whether transthyretin amyloidosis (ATTR) is causing cardiac amyloidosis, a condition where abnormal proteins build up in the heart muscle. It helps tell ATTR apart from AL amyloidosis and often avoids the need for a heart biopsy. Expect to spend 3 to 4 hours.
What the research says
It can replace a biopsy: in 1,217 people, bone tracer heart scans were more than 99% sensitive for ATTR, and grade 2 or 3 uptake with no abnormal blood proteins was 100% specific (Gillmore JD et al., Circulation, 2016) [2]
It separates ATTR from AL: in 45 people, a PYP heart-to-chest uptake ratio above 1.5 identified ATTR with 97% sensitivity and 100% specificity (Bokhari S et al., Circ Cardiovasc Imaging, 2013) [3]
Key takeaways
A PYP scan checks for ATTR cardiac amyloidosis.
It helps distinguish ATTR from AL amyloidosis, which is treated differently.
A tracer is injected, and the scan is done about 3 hours later.
Grades 2 and 3 suggest ATTR; grade 0 is negative.
It often avoids the need for a heart biopsy.
What is a cardiac PYP scan?
In ATTR amyloidosis, a protein called transthyretin misfolds and builds up in the heart, making it stiff. The PYP tracer sticks to these deposits. By comparing how much tracer the heart takes up with how much the ribs take up, doctors can tell whether ATTR is likely. Some centers now use a similar tracer called HMDP. Sources: [1]
Why it's done
The scan helps match you to the right treatment.
Confirm ATTR cardiomyopathy.
Distinguish ATTR from AL amyloidosis, which needs different treatment.
Evaluate unexplained thickening of the heart muscle or heart failure.
Avoid a more invasive heart biopsy. Sources: [1]
Blood and urine tests for abnormal proteins are usually done alongside the scan to rule out AL amyloidosis. Sources: [2]
How to prepare
No special preparation is needed.
Leave jewelry and valuables at home.
Wear comfortable clothes without metal and empty your pockets.
Urinating before the scan may make you more comfortable. Sources: [1]
What happens during the test
Total time at the facility is about 3 to 4 hours.
An IV is placed in your arm and the tracer is injected.
You wait about 3 hours while the tracer circulates.
You lie on your back on the scanner bed, possibly with your arms raised.
A SPECT/CT camera takes images focused on your chest while you lie still for about 45 minutes. Sources: [1]
Risks
The PYP scan is generally low risk. It uses a low level of radiation. You can return to work, eating and driving right away. Sources: [1]
What the results mean
Results may take a few days.
Grade | Heart uptake compared with ribs | What it means |
0 | No heart uptake | Negative |
1 | Less than ribs | Unclear; more tests may be needed |
2 | Equal to ribs | Positive for ATTR |
3 | Greater than ribs | Positive for ATTR |
Results may take a few days. When the scan shows grade 2 or 3 and blood and urine tests show no abnormal light-chain proteins, ATTR can be diagnosed without a biopsy with very high accuracy. Sources: [1, 2, 3]
Conclusion
The cardiac PYP scan is the standard noninvasive test for ATTR cardiac amyloidosis. It can confirm the diagnosis without a biopsy and guide you toward treatments designed for this condition.
Keep learning: read about cardiac amyloidosis and the heart biopsy.
Frequently asked questions
What is a cardiac PYP scan?
A nuclear scan that checks for ATTR cardiac amyloidosis.
What does PYP stand for?
Pyrophosphate, the tracer used.
How long does the PYP scan take?
About 3 to 4 hours in total, including a 3-hour wait.
Does it hurt?
Only the IV needle.
Do I need to prepare?
No special preparation is needed.
What does a grade 2 or 3 mean?
It suggests ATTR amyloidosis.
Can it replace a heart biopsy?
Often, when combined with blood and urine tests.
Is the radiation safe?
The dose is low.
Can I drive afterward?
Yes.
When will I get results?
Usually within a few days.
Related Reading
What Is Cardiac Amyloidosis? Symptoms, Causes, Diagnosis and Treatment the condition the scan detects.
ATTR-CM (Transthyretin Amyloid Cardiomyopathy): The Rare Heart Condition Caused by Protein Clumps — Explained in Plain English the type of amyloidosis it confirms.
Heart Biopsy (Endomyocardial Biopsy): Procedure, Risks and Results the invasive test it can often replace.
SPECT Scan: How It Works, What It Shows and What to Expect 3D nuclear imaging used in this scan.
Nuclear Medicine Imaging: How Tracer Scans Work, Safety and Results an overview of tracer-based tests.
References
Cleveland Clinic. Cardiac PYP Scan: Test and Results. Cleveland Clinic. Last updated September 12, 2025. https://my.clevelandclinic.org/health/diagnostics/cardiac-pyp-scan
Gillmore JD, Maurer MS, Falk RH, et al. Nonbiopsy diagnosis of cardiac transthyretin amyloidosis. Circulation. 2016;133(24):2404-2412. PMID 27143678. https://doi.org/10.1161/CIRCULATIONAHA.116.021612
Bokhari S, Castaño A, Pozniakoff T, et al. (99m)Tc-pyrophosphate scintigraphy for differentiating light-chain cardiac amyloidosis from the transthyretin-related familial and senile cardiac amyloidoses. Circ Cardiovasc Imaging. 2013;6(2):195-201. PMID 23400849. https://doi.org/10.1161/CIRCIMAGING.112.000132
Medical disclaimer
This article is for general education only and does not replace advice from a qualified healthcare professional. Talk to your doctor about your own diagnosis and treatment, and seek emergency care right away for severe or sudden symptoms.
Comments