Frequency of hereditary transthyretin amyloidosis among elderly patients with transthyretin cardiomyopathy

Transthyretin amyloid cardiomyopathy (ATTR-CM) is increasingly recognized as a cause of heart failure in the elderly. Although wild-type transthyretin amyloidosis is the most frequent form of ATTR-CM found in the elderly, hereditary transthyretin amyloidosis (ATTRv) can also occur. We sought to determine the prevalence of ATTRv among elderly ATTR-CM patients, identify predictors of ATTRv and evaluate the clinical consequences of positive genetic testing in this population. Prevalence of ATTRv in elderly ATTR-CM patients (≥70 years) was assessed in a cohort of 300 consecutive ATTR-CM patients (median age 78 years at diagnosis, 82% ≥70 years, 16% female, 99% Caucasian). ATTRv was diagnosed in 35 (12%; 95% confidence interval [CI] 3.1–8.8) and 13 (5.3%; 95% CI 5.6–26.7) patients in the overall cohort and in those ≥70 years, respectively. Prevalence of ATTRv among elderly female patients with ATTR-CM was 13% (95% CI 2.1–23.5). Univariate analysis identified female sex (odds ratio [OR] 3.66; 95% CI 1.13–11.85; p = 0.03), black ancestry (OR 46.31; 95% CI 3.52–Inf; p = 0.005), eye symptoms (OR 6.64; 95% CI 1.20–36.73; p = 0.03) and polyneuropathy (OR 10.05; 95% CI 3.09–32.64; p<0.001) as the only factors associated with ATTRv in this population. Diagnosis of ATTRv in elderly ATTR-CM patients allowed initiation of transthyretin-specific drug treatment in 5 individuals, genetic screening in 33 relatives from 13 families, and identification of 9 ATTRv asymptomatic carriers. Hereditary transthyretin amyloidosis is present in a substantial number of ATTR-CM patients aged ≥70 years. Identification of ATTRv in elderly patients with ATTR-CM has clinical meaningful therapeutic and diagnostic implications. These results support routine genetic testing in patients with ATTR-CM regardless of ageThis study has been funded by Instituto de Salud Carlos III (ISCIII) through the projects ‘PI18/0765 & PI20/01379’ (co-funded by European Regional Development Fund/European Social Fund ‘A way to make Europe’/‘Investing in your future’). AMB receives grant support by ISCIII (CM20/002209). The CNIC is supported by the ISCIII, MCIN, the Pro-CNIC Foundation, and the Severo Ochoa grant (CEX2020-001041-S