The Mayo ATTR‐CM score versus other diagnostic scores and cardiac biomarkers in patients with suspected cardiac amyloidosis

Aims: Several scores were developed to help the diagnosis of cardiac amyloidosis (CA). The most recent one, being the Mayo transthyretin amyloidosis cardiomyopathy (ATTR-CM) score, was not externally validated. We compared the diagnostic performance of the ATTR-CM score with previous tools (increased wall thickness [IWT] score, AMYLoidosis Index [AMYLI] score, and cardiac biomarkers) in a cohort of patients evaluated for a suspicion of CA. Methods and results: We analysed 362 consecutive patients referred to a third-level centre for suspected CA. Overall, 132 (36%) had transthyretin CA (ATTR-CA), and 91 (25%) immunoglobulin light chain CA (AL-CA); CA was excluded in 139 (38%). ATTR-CM score had a good diagnostic performance to distinguish ATTR-CA from AL-CA or no CA, with an area under the curve (AUC) of 0.795 (95% confidence interval [CI] 0.747-0.842, p < 0.001), and ATTR-CA from no CA (AUC 0.822, 95% CI 0.774-0.871, p < 0.001). Results were consistent in both patients with preserved (AUC 0.787, 95% CI 0.726-0.848, p < 0.001), and reduced or mildly reduced ejection fraction (AUC 0.790, 95% CI 0.709-0.871, p < 0.001). The ATTR-CM score showed a better discrimination compared to IWT and AMYLI score to distinguish ATTR-CA from AL-CA or no CA (p = 0.002), but not to distinguish ATTR-CA from no CA (p = 0.270). Diagnostic accuracy was significantly higher for the ATTR-CM score as compared to the rule-in cut-off of high-sensitivity troponin T. Conclusion: The Mayo ATTR-CM score has a good performance in identifying patients with ATTR-CA, with also better discrimination power when compared to other scores and biomarkers.