Can echocardiographic strain imaging find cardiac amyloidosis in patients with left ventricular hypertrophy?
Echocardiographic strain imaging is a non-invasive tool that measures how the heart muscle moves and deforms during contraction. In patients with left ventricular hypertrophy (LVH), a thickened heart muscle, doctors sometimes suspect cardiac amyloidosis (CA) — a condition where abnormal protein deposits stiffen the heart. Strain imaging can reveal a pattern called "apical sparing," where the tip of the heart (apex) moves better than the middle and base. This pattern is a red flag for CA. However, the test is not perfect, and its accuracy depends on the specific threshold used and the patient's other conditions.
What the research says
A 2024 systematic review and meta-analysis pooled data from 22 studies (over 4,100 patients) and found that the apical sparing ratio (ASR) from strain imaging has moderate accuracy for detecting CA in LVH patients. At an optimal threshold of 0.83, the test had a sensitivity of 73% and specificity of 77%, with an area under the curve (AUC) of 0.81, indicating good but not excellent diagnostic performance 1. In patients with severe aortic stenosis, accuracy was slightly lower (sensitivity 65%, specificity 74%, AUC 0.79) 1.
Other studies support these findings. One study of 85 patients with LVH and heart failure found that a higher strain relative apical sparing ratio (2.2 vs. 1.03) was significantly associated with CA 4. Another study showed that adding right ventricular free-wall strain (a measure of the right heart's deformation) to the apical sparing ratio improved diagnostic accuracy, especially in patients with less extreme wall thickening 5. Additionally, left atrial strain measurements may also help distinguish CA from other causes of LVH 6.
It is important to note that strain imaging is just one piece of the puzzle. The studies show high variability (heterogeneity) across different populations, meaning results can differ from one patient group to another 1. Therefore, a positive or negative strain test should be interpreted alongside other clinical findings and confirmatory tests like cardiac biopsy or nuclear imaging.
What to ask your doctor
- What is my apical sparing ratio on strain imaging, and what does it suggest about the possibility of cardiac amyloidosis?
- Would adding right ventricular strain or left atrial strain measurements improve the accuracy of my diagnosis?
- If my strain test is borderline, what other tests (like cardiac MRI or nuclear scan) would you recommend to confirm or rule out amyloidosis?
- How does my other medical condition, such as aortic stenosis or high blood pressure, affect the interpretation of my strain imaging results?
- Should I be referred to a cardiologist specializing in amyloidosis for further evaluation?
This question is drawn from common patient questions about Cardiology and answered using cited medical research. We do not provide individualized advice.