Changes in the diagnostic trajectory of transthyretin cardiac amyloidosis over six years

Awareness of transthyretin amyloid cardiomyopathy (ATTR-CM) has increased over the years due to diagnostic and therapeutic developments. Timely initiation of novel disease-modifying treatments improves both morbidity and mortality, which underlines the necessity for a prompt diagnosis. Nevertheless, early diagnosis of ATTR-CM remains challenging. This is a retrospective observational cohort study of patients diagnosed with ATTR-CM. Between 2016 and 2023, 87 patients were diagnosed with cardiac amyloidosis of which 65 (75%) patients with ATTR-CM and 22 (25%) patients with light chain amyloidosis. This study included 65 ATTR-CM patients (mean age 77 +/- 7 years; 86% male) of whom 59 (91%) with wild-type ATTR-CM (ATTRwt) and six (9%) with variant ATTR-CM. We observed a surge in ATTR-CM diagnoses from 3 patients/year (2016-2020) to 16 patients/year (2021-2023), driven by ATTRwt. Nevertheless, the interval between the onset of heart failure symptoms and ATTR-CM diagnosis has not changed significantly (2016-2020 27.3 months [18.6-62.4]; 2021-2023 30.0 months [8.6-57.2]; p = 0.546), driven by time to referral. Red flags for ATTR-CM preceded diagnosis by several years: left ventricular hypertrophy (79%, 5.8 years [3.3-7.0]) and carpal tunnel syndrome (49%, 6.8 years [2.3-12.1]). Despite the presence of typical red flags, symptom-to-diagnosis duration has remained similar driven by time to referral. Improved recognition of red flags for ATTR-CM could reduce the time to diagnosis and improve overall recognition.