Diagnostic Pathways to Wild-Type Transthyretin Amyloid Cardiomyopathy: a Multicenter Network Study

Background: Epidemiology of wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) remains poorly defined. A better characterization of pathways leading to ATTRwt-CA diagnosis is of key importance, and potentially informative of disease course and prognosis. Objectives: To describe characteristics of contemporary pathways leading to ATTRwt-CA diagnosis, and their potential association with survival. Methods: This was a retrospective study of patients diagnosed with ATTRwt-CA at 17 Italian referral centres for CA. Patients were categorized into different 'pathways' according to the medical reason that triggered the diagnosis of ATTRwt-CA (hypertrophic cardiomyopathy [HCM] pathway, heart failure [HF] pathway, incidental imaging or incidental clinical pathway). Prognosis was investigated with all-cause mortality as endpoint. Results: 1281 ATTRwt-CA patients were included in the study. Diagnostic pathway leading to ATTRwt-CA diagnosis was HCM in 7% of patients, HF in 51%, incidental imaging in 23%, incidental clinical in 19%. Patients in the HF pathway, as compared to the others, were older and had a greater prevalence of NYHA III-IV and chronic kidney disease. Survival was significantly worse in the HF vs. other pathways, but similar among the three others. In multivariate model, older age at diagnosis, NYHA III-IV and some comorbidities but not the HF pathway were independently associated with worse survival. Conclusions: Half of contemporary ATTRwt-CA diagnoses occur in a HF setting. These patients had worse clinical profile and outcome than those diagnosed either due to suspected HCM or incidentally, although prognosis remained primarily related to age, NYHA functional class and comorbidities rather than the diagnostic pathway itself. This article is protected by copyright. All rights reserved.