Comparative diagnostic performance of clinical scores for transthyretin amyloid cardiomyopathy across disease stages
Y Haruki, T Nabeta, S Nakahara, Y Watanabe, S Iikura, Y Takigami, Y Eda, Y Iida, Y Ikeda, S Ishii, J AkoAbstract
Background
Transthyretin amyloid cardiomyopathy (ATTR-CM) is an infiltrative cardiomyopathy which is associated with heart failure and high mortality. Early diagnosis and treatment with disease-modifying therapy are crucial in ATTR-CM. Although several diagnostic scores for ATTR-CM have been developed, comparative data among these scores are limited, and their performance in early-stage disease remains unclear.
Purpose
We aimed to evaluate clinical characteristics across disease stages of ATTR-CM and compare the stage-specific diagnostic performance of existing scoring systems.
Methods
We retrospectively enrolled patients diagnosed with ATTR-CM and those with suspected cardiac amyloidosis who underwent 99mTc-pyrophosphate scintigraphy; patients not diagnosed with ATTR-CM were defined as controls. ATTR-CM was diagnosed according to the ESC consensus statement. Patients with ATTR-CM were stratified according to the National Amyloidosis Centre (NAC) staging system. We evaluated the following diagnostic scores: the Mayo score, Kumamoto criteria [high-sensitivity cardiac troponin T (hs-cTnT) cut-off 0.031 ng/mL], modified Kumamoto criteria (hs-cTnT cut-off 0.015 ng/mL), and T-Amylo score. Diagnostic performance was assessed in the overall cohort and separately in early-stage patients (NAC stage I) using comparisons with controls.
Results
We included 76 ATTR-CM patients (NAC stage I, 27; II, 31; III, 18) and 135 controls. Compared with controls, patients with ATTR-CM were older, predominantly male, had higher hs-cTnT, and greater left ventricular wall thickness. With advancing stage, prevalence of atrial fibrillation increased, and left ventricular ejection fraction declined. In the overall cohort, the Mayo score demonstrated the highest area under the curve (AUC: 0.858), sensitivity (81.6%), and negative predictive value (86.7%), followed by the Kumamoto criteria with the next highest AUC (0.791). In NAC stage I, the Mayo score remained the best-performing score (AUC: 0.816). The modified Kumamoto criteria showed higher sensitivity (69.2% vs 53.8%) and AUC (0.760 vs 0.726) compared with the original Kumamoto criteria in NAC stage I. The T-Amylo score consistently showed high specificity but low sensitivity, resulting in the lowest AUC (0.714 overall; 0.644 NAC stage I) among the scores. (Figure1,2)
Conclusion
Among patients with suspected ATTR-CM, the Mayo score consistently demonstrated the highest sensitivity and diagnostic accuracy across both the overall cohort and early-stage disease. Although the Kumamoto criteria also showed good diagnostic accuracy, the modified version with a lower troponin T cut-off achieved superior sensitivity and AUC in early-stage disease. These findings may help optimize early detection strategies for ATTR-CM.