Frequency of hereditary transthyretin amyloidosis among elderly patients with transthyretin cardiomyopathy

AIMS: 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. METHODS AND RESULTS: 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. CONCLUSIONS: 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 age.