Prevalence, characteristics and outcomes of older patients with hereditary versus wild‐type transthyretin amyloid cardiomyopathy

Aims Transthyretin amyloid cardiomyopathy (ATTR‐CM) is often assumed to be associated with wild‐type TTR genotype (ATTRwt) in elderly patients (aged ≥70), some of whom are not offered genetic testing. We sought to estimate the prevalence, clinical characteristics and prognostic implications of transthyretin (TTR) variants among elderly patients diagnosed with ATTR‐CM. Methods and results Data from consecutive patients over 70 years of age diagnosed with ATTR‐CM at the UK National Amyloidosis Centre between January 2010 and August 2022 were retrospectively evaluated. All patients underwent clinical evaluation, biochemical tests, echocardiography and TTR genotyping. The study outcome was all‐cause mortality. The study population consisted of 2029 patients with ATTR‐CM (median age 79 years at diagnosis, 13.5% females, 80.4% Caucasian). Variant ATTR‐CM (ATTRv‐CM) was diagnosed in 20.7% ( n = 421) of the study population of whom 327 (77.7%) carried V122I, 47 (11.2%) T60A, 16 (3.8%) V30M and 31 (7.3%) other pathogenic TTR variants. During a median (range) follow‐up of 29 (12–48) months, ATTRv‐CM was associated with increased all‐cause mortality compared to ATTRwt‐CM, with the poorest survival observed in V122I‐associated ATTRv‐CM ( p < 0.001). Univariable and multivariable logistic regression analyses in those with ATTR‐CM showed younger age at diagnosis (odds ratio [OR] 0.85 per year, p < 0.001), female sex (OR 2.73, p < 0.001), Afro‐Caribbean ethnicity (OR 65.5, p < 0.001), atrial fibrillation (OR 0.65, p = 0.015), ischaemic heart disease (OR 0.54, p = 0.007), peripheral polyneuropathy (OR 5.70, p < 0.001) and orthostatic hypotension (OR 6.29, p < 0.001) to be independently associated with ATTRv‐CM. Conclusion Up to 20.7% of elderly patients with ATTR‐CM have a pathogenic TTR variant. These findings support routine sequencing of the TTR gene in all patients with ATTR‐CM regardless of age.