Sex-based imaging and ECG phenotypes in transthyretin cardiac amyloidosis

Abstract Background and aim Transthyretin cardiac amyloidosis (ATTR-CM) displays substantial heterogeneity in both clinical presentation and imaging findings. While a male predominance is well-established, sex-specific differences in imaging expression and disease phenotype remain underexplored. In this study, we systematically evaluated associations between three distinct nuclear imaging uptake patterns—right ventricular (RV) uptake, left ventricular (LV) apical sparing, and soft tissue uptake—and clinical, electrocardiographic (ECG), and echocardiographic variables, with a particular emphasis on potential sex-based differences in disease manifestation. Methods We included patients with confirmed ATTR-CM. Imaging phenotypes evaluated on planar and SPECT imaging included RV uptake, apical sparing pattern of tracer distribution, and extracardiac soft tissue uptake. These patterns were compared between male and female patients to assess potential sex-related differences in disease expression. Results We studied 95 patients (69 males, 26 females) with a mean age of 81.8 ± 7.6 years. All patients had grade 3 Perugini. Right ventricular uptake was observed in 39% of the cohort, apical sparing in 29%, and soft tissue uptake was identified in 47%. Male patients had significantly higher rates of atrioventricular block (27.5% vs. 0%, p = 0.003), reduced LV Ejection Fraction (