Can an apical sparing ratio help detect cardiac amyloidosis in my heart?

The apical sparing ratio (ASR) is a measurement from an echocardiogram (heart ultrasound) that looks at how the heart muscle stretches. In cardiac amyloidosis, the bottom part of the heart (apex) often moves better than the upper parts (base), creating a pattern called 'apical sparing.' This ratio compares strain (stretching) at the apex to strain at the base and middle of the heart. While ASR can suggest cardiac amyloidosis, it is not a standalone test. Doctors use it along with other imaging and lab tests to make a diagnosis.

What the research says

Multiple studies show that ASR has moderate accuracy for detecting cardiac amyloidosis. A large meta-analysis of 22 studies (over 4,000 patients) found that an ASR threshold of 0.83 had a sensitivity of 73% and specificity of 77%—meaning it correctly identifies about 3 out of 4 people with the disease, but also gives false positives in about 1 in 4 people without it ¹⁶. Another meta-analysis of 41 studies reported similar results: sensitivity 66% and specificity 83% ³. The test works better for certain types of amyloidosis. For AL (light chain) amyloidosis, specificity reached 93%, but sensitivity was lower at 60% ³. For ATTR (transthyretin) amyloidosis, sensitivity was 64% and specificity 82% ³. In people with severe aortic stenosis (a common heart valve condition), ASR's accuracy drops slightly, with sensitivity 65% and specificity 74% ¹⁶. Other research confirms that ASR is a useful clue but not definitive. One study found that among patients referred for a nuclear scan (bone scintigraphy) to check for ATTR amyloidosis, ASR and other strain ratios helped predict the disease, but the best results came from combining multiple echocardiographic parameters ⁷. In patients with both aortic stenosis and suspected amyloidosis, a higher 'relative apical longitudinal strain' (RALS) was linked to amyloidosis ⁸. Overall, ASR is a helpful screening tool, but it should be part of a broader evaluation that includes other imaging (like cardiac MRI or nuclear scans) and lab tests ²⁴⁵.

What to ask your doctor

• What is my apical sparing ratio, and what does it suggest for my heart?
• Should I have additional tests like a cardiac MRI or a nuclear scan (bone scintigraphy) to confirm or rule out cardiac amyloidosis?
• If my ASR is abnormal, what are the next steps to diagnose the specific type of amyloidosis (AL or ATTR)?
• Could my other heart conditions (like aortic stenosis or high blood pressure) affect the accuracy of the ASR result?
• How reliable is the ASR test compared to other methods for detecting cardiac amyloidosis?