RWT/SaVR Ratio displays strong diagnostic performance to identify transthyretin amyloid cardiomyopathy in females: implications for sex-specific echocardiographic thresholds

Abstract Aims Transthyretin cardiomyopathy (ATTR-CM) is a progressive, life-threatening infiltrative disorder with reportedly lower prevalence in women. While echocardiographic red flags for identifying ATTR-CM have been established in populations overrepresented by men, their diagnostic utility is inadequately studied in women. We assessed the diagnostic accuracy of echocardiographic red flags and electrocardiography in a well-characterized, female population with hypertrophied left ventricles to differentiate ATTR-CM from left ventricular hypertrophy (LVH). Methods and results We compared echocardiographic red flags and electrocardiography in 62 female patients with an interventricular septal thickness of >12 mm, divided equally into well-defined ATTR-CM (n = 31) and age-matched LVH. ATTR-CM displayed higher relative wall thickness (RWT), higher values for relative apical sparing (RELAPS), and lower S-wave in lead aVR (SaVR) than LVH. Left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) did not differ between groups. RWT/SaVR ratio displayed stronger diagnostic performance to identify ATTR-CM (AUC = 0.97) when compared with RELAPS (AUC = 0.83) and RWT (AUC = 0.82). Further, RELAPS demonstrated lower and SaVR higher optimal diagnostic cut-offs than those previously published in predominant male cohorts. Conclusion In a well-characterized, single-centre, female population with hypertrophied left ventricles, RWT/SaVR outperformed conventional echocardiographic red flags and shows promise for diagnosing ATTR-CM. Our findings also highlight the need for sex-specific cut-offs, but generalizability is limited by a single-centre design and predominance of the Val30Met genotype. Validation in larger prospective cohorts is warranted.