PURPOSE: Bone tracers have been validated for many years in detecting transthyretin (TTR) cardiac amyloidosis (CA) (TTR-CA). Several new studies, however, suggest conflicting results. Our study aimed to systematically evaluate the accuracy of bone radiotracers for diagnosing and distinguishing TTR-CA via a systematic review and meta-analysis.
METHODS: We retrieved PubMed, the Cochrane Library, ScienceDirect, and DOAJ database, date up to 10 July 2020, for researches assessing the performance of bone tracer in diagnosing and differentiating TTR-CA. The meta-analysis was conducted through Stata 16 software, and the risk of bias for the included studies was assessed by the QUADAS-2 tool. Moreover, we made a comprehensive review.
RESULTS: Fourteen articles were included for the systematic review, and 9 for the meta-analysis. The pooled sensitivity was 0.97 [95% confidence interval (95% CI) 0.85-0.99)] with heterogeneity (I2 = 73.5, 95% CI 55.6-91.2), and the specificity was 0.92 (95% CI 0.82-0.96) with heterogeneity (I2 = 42.0, 95% CI 0.0-86.9). The pooled PLR and NLR were 11.49 (95% CI 5.07-26.0) and 0.03 (95% CI 0.01-0.18), respectively. The DOR was 341 (95% CI 53-2194), and the AUC was 0.96 (95% CI 0.94-0.97).
CONCLUSION: The findings evidence that the bone radiotracer provides high accuracy of diagnosing TTR-CA and plays a modest role in differentiating TTR-CA from AL-CA, which is a valuable noninvasive approach. 99mTc-HMDP may be more accurate than 99mTc-PYP, 99mTc-DPD, and 18F-NaF in the TTR-CA detecting process, and 18F-NaF is a promising bone tracer to diagnose and distinguish TTR-CA.