# Cardiac magnetic resonance imaging and cardiac scintigraphy in the diagnosis of cardiac amyloidosis: A meta-analysis of 4866 patients

## TL;DR

This study compares two non-invasive methods for diagnosing cardiac amyloidosis and finds that cardiac scintigraphy with a specific tracer is more accurate than MRI.

## Contribution

The study provides a meta-analysis comparing the diagnostic accuracy of cardiac MRI and scintigraphy for cardiac amyloidosis.

## Key findings

- Cardiac scintigraphy with 99mTc-HMDP shows the highest specificity for diagnosing cardiac amyloidosis.
- CMR imaging has lower specificity compared to scintigraphy, making it less reliable for diagnosing the condition.
- Different radiotracers in scintigraphy vary in diagnostic accuracy, with 99mTc-DPD showing the highest sensitivity.

## Abstract

Cardiac amyloidosis (CA) impacts about 20 % of elderly heart failure patients, leading to myocardial dysfunction and life-threatening risks. However, it often remains undetected due to the significant risks associated with invasive biopsies. This highlights the critical need for safer and accurate non-invasive diagnostic techniques.

To compare the diagnostic value of Cardiac Magnetic Resonance (CMR) imaging and Cardiac Scintigraphy Imaging in the diagnosis of CA.

A comprehensive literature search across PubMed, Scopus, Web of Science, and Cochrane databases yielded studies that utilized CMR or cardiac scintigraphy for diagnosing CA. QUADAS-2 was employed for quality assessment.

From 7117 records, 35 studies involving 4866 patients were analyzed. Cardiac scintigraphy demonstrated higher sensitivity and specificity across different radiotracers, with 99mTc-HMDP showing the highest specificity (1.00, 95 % CI: 0.93–1.00) and 99mTc-DPD the highest sensitivity (0.93, 95 % CI: 0.89–0.95). CMR imaging showed variable diagnostic accuracy with a sensitivity of 0.83 (95 % CI: 0.81–0.85) and a lower specificity of only 0.53 (95 % CI: 0.50–0.56).

Cardiac scintigraphy, particularly with 99mTc-HMDP, offers superior diagnostic accuracy for CA compared to CMR imaging. Controlled, randomized, prospective studies directly comparing these non-invasive techniques are essential to validate these findings.

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•Cardiac scintigraphy with 99mTc-HMDP enables accurate and reliable diagnosis of cardiac amyloidosis.•Different radiotracers used in Cardiac Scintigraphy exhibit varying levels of diagnostic accuracy.•CMR is useful for cardiac imaging but less specific than scintigraphy in distinguishing amyloidosis.•Diagnostic method selection should be individualized to each patient's clinical scenario.

Cardiac scintigraphy with 99mTc-HMDP enables accurate and reliable diagnosis of cardiac amyloidosis.

Different radiotracers used in Cardiac Scintigraphy exhibit varying levels of diagnostic accuracy.

CMR is useful for cardiac imaging but less specific than scintigraphy in distinguishing amyloidosis.

Diagnostic method selection should be individualized to each patient's clinical scenario.