Early detection of transthyretin cardiac amyloidosis in carpal tunnel syndrome patients using myocardial work and strain imaging
R Machado, S Maia, E Moreira, P Palma, H Moreira, L Vieira, M Fonseca, C Sousa, A Martins, S Pimenta, J Quelhas-Santos, E MartinsAbstract
Background
Carpal tunnel syndrome (CTS) has emerged as an early clinical marker of transthyretin cardiac amyloidosis (ATTR-CA) and may be associated with adverse cardiovascular outcomes. Early diagnosis is increasingly relevant given recent advances in ATTR-CA therapy. Conventional echocardiography may suggest CA through unexplained left ventricular (LV) wall thickening, often with preserved ejection fraction. Advanced techniques, including strain imaging, enhance non-invasive CA detection. Myocardial work (MW), which integrates myocardial deformation and afterload, has shown potential for LV functional assessment. Preliminary data suggest MW indices are reduced in CA and may carry prognostic value. However, their utility for early identification of ATTR-CA in CTS patients remains underexplored.
Purpose
To explore global longitudinal strain (GLS) and MW indices for early detection of ATTR-CA in patients with CTS.
Methods
Patients were enrolled from a cross-sectional study investigating the association between idiopathic CTS and ATTR amyloidosis. All underwent clinical evaluation, echocardiography, and 99mTc-DPD scintigraphy. GLS and MW indices, including global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE), were assessed via speckle-tracking echocardiography. LV hypertrophy was defined as a wall thickness ≥12 mm. Patients with inadequate image quality were excluded. Continuous variables are reported as median (interquartile range) and categorical variables as counts and percentages.
Results
Twenty patients were analysed with a median age of 67.5 (15.5) years, and 45% of patients were male (9/20). ATTR-CA was diagnosed in 3 (15%) patients, all older males. LV hypertrophy was present in all ATTR-CA patients and 8 (47%) of non-CA patients. ATTR-CA patients exhibited more impaired GLS [-13.3 (4.8) vs. -16.0 (4.6) %] and lower MW indices, particularly GCW [1583 (963.5) vs. 2022 (732) mmHg%] compared with non-CA patients.
Conclusion
In CTS patients, GLS and MW indices, particularly GCW, showed a consistent pattern of impairment in ATTR CA, even in the presence of overlapping LV hypertrophy. These parameters may help identify patients who warrant further diagnostic evaluation.Boxplots of GLS and MW indicesFor image description, please refer to the figure legend and surrounding text.