Phenotype and prognostic factors in geriatric and non-geriatric patients with transthyretin cardiomyopathy

Aims: Transthyretin cardiac amyloidosis (ATTR-CM) may be an underestimated cause of heart failure among geriatric patients and represent a unique phenotype and prognostic profile.

Methods and results: This retrospective, observational, cohort study characterizes cardiac and extracardiac disorders at diagnosis and assesses prognosis among ATTR-CM patients based on age (geriatric vs. non-geriatric) and amyloidosis subtype (wild type, ATTRwt and hereditary, ATTRv). In total, 943 patients with ATTR-CM were included, of which 306 had ATTRv and 637 had ATTRwt. Among these, 331 (35.1%) were non-geriatric (<75 years), and 612 (64.9%) were geriatric (≥75 years). The population exhibited conduction abnormalities, atrial fibrillation and ischaemic heart disease that progressively deteriorated with age. Among ATTRwt patients, peripheral neuropathy, neurovegetative symptoms, and hearing loss were present across all age groups, but reports of carpal tunnel symptoms or surgery decreased with age. Conversely, among ATTRv patients, reports of extracardiac symptoms increased with age and Val122ILe mutation was highly prevalent among geriatric patients. The 3-year survival was higher among non-geriatric ATTR-CM patients (76%) than geriatric patients (55%) and predictors of 3-year mortality differed. Notably, predictors identified among geriatric patients were alkaline phosphatase (ALP) (HR = 1.004, 95% CI: [0.001-1.100)], troponin T hs (HR = 1.005, 95% CI: [1.001-1.120)] and tricuspid insufficiency (HR = 1.194, 95% CI: [1.02-1.230)]. Whereas, among non-geriatric patients, NT-proBNP (HR = 1.002, 95% CI: [1.02-1.04], global longitudinal strain (HR = 0.95, 95% CI: [0.922-0.989], and glomerular filtration rate (HR = 0.984, 95% CI: [0.968-1.00) were identified. We propose a 3-stage prognostic staging system combining troponin T hs (≥44 ng/L) and ALP levels (≥119 UI/L). In the geriatric population, this model discriminated survival more precisely than the National Amyloidosis Centre staging, particularly for classifying between stage 1 (82%), stage 2 (50%) and stage 3 (32%) for ATTRv and ATTRwt.

Conclusions: These diagnostic and prognostic indicators, along with ATTR subtype, highlight the distinct characteristics of this important, geriatric ATTR-CM patient group. Recognizing these mortality markers can be valuable for geriatricians to improve the prognostic quality management of geriatric patients with ATTR-CM.