Non-invasive Imaging Findings of Wild-type Transthyretin Amyloid Cardiomyopathy in Women: A Retrospective Study.

Objective: Wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) predominantly affects males; however, female patients can also develop this condition. This study assessed the non-invasive imaging features of ATTRwt-CM in female patients.

Methods: In this study, 106 consecutive patients diagnosed with ATTRwt-CM were retrospectively analyzed, evaluating sex-related differences in imaging features, including echocardiography, cardiac magnetic resonance (CMR), and 99mTc-labeled pyrophosphate (99mTc-PYP) scintigraphy.

Results: 12 of 106 patients (11.3%) were female. They were significantly older at diagnosis (75 years [interquartile range, 71-79 years] vs. 79 years [77-83 years]; p<0.01). The proportion of female patients increased with age, from 7.5% (6/80) in those aged <80 years to 23.1% (6/26) in those aged ≥80 years. CMR-measured left ventricular ejection fraction (LVEF) was significantly higher in female patients (50.0% [42.0-61.0%] vs. 59.5% [44.3-72.3%]; p=0.04). No significant sex-related differences in LV mass and global longitudinal strain were observed. In T1 mapping, no significant difference in native T1 was observed; however, the extracellular volume fraction (ECV) was significantly lower in female patients (54.2% [46.5-66.0%] vs. 50.4% [42.0-55.0%]; p=0.04). Furthermore, no significant difference in myocardial T2 value was observed. Late gadolinium enhancement was more extensively observed in males than in females. The heart-to-contralateral ratio in 99mTc-PYP scintigraphy was significantly lower among female patients (1.88 [1.70-2.04] vs. 1.64 [1.58-1.74]; p=0.02).

Conclusions: CMR findings revealed that females exhibited higher LVEF, lower ECV, and weaker cardiac uptake on 99mTc-PYP scintigraphy, indicating a milder myocardial amyloid burden. No significant sex-related differences in echocardiographic parameters or other CMR indices were observed.