The Impact of Active Ascertainment on Sex-Specific Differences in the Prevalence and Phenotype of Transthyretin Cardiac Amyloidosis: The Screening for Cardiac Amyloidosis With Nuclear Imaging in Minority Populations Study

Abstract

Transthyretin cardiac amyloidosis (ATTR-CA) is disproportionately diagnosed in older men. However, studies suggest that the true prevalence of ATTR-CA in women may be greater than previously reported. The Screening for Cardiac Amyloidosis with Nuclear Imaging in Minority Populations (SCAN-MP) study uses nuclear scintigraphy to identify ATTR-CA in self-identified Black and Caribbean Hispanic participants ≥60 years old with heart failure and left ventricular hypertrophy. We characterized the sex distribution and phenotypic characteristics of ATTR-CA in this active ascertainment cohort in comparison with a population of patients with ATTR-CA who were referred to a tertiary care academic center outpatient clinic. The active ascertainment SCAN-MP cohort had a greater proportion of women than did the referral clinic cohort (31.3% vs 13.3%, p = 0.016). This was mainly attributed to the greater proportion of women with wild-type ATTR-CA (27.8% vs 7.1%, p = 0.012). Women with ATTR-CA in the active ascertainment cohort exhibited higher left ventricular ejection fraction than did those in the referral cohort (61% vs 50%, p = 0.011), lower left ventricular mass index (110 vs 148 g/m², p = 0.014), and smaller posterior wall thickness (1.4 vs 1.6 cm, p = 0.01). An active ascertainment strategy for ATTR-CA identification showed a greater proportion of women than did a referral cohort, driven predominantly by the greater proportion of women with wild-type ATTR-CA, and echocardiographic evidence of a less severe phenotype. In conclusion, efforts for early identification of ATTR-CA in women are critical for reducing sex disparities in this clinically treatable disease.

Keywords: SCAN-MP; sex disparities; transthyretin cardiac amyloidosis; women.