A national survey on prevalence of possible echocardiographic red flags of amyloid cardiomyopathy in consecutive patients undergoing routine echocardiography: study design and patients characterization - the first insight from the AC-TIVE Study

Raising the suspicion of amyloid cardiomyopathy (AC) is essential to orient additional tests and to achieve an early diagnosis before the development of clinically overt disease. Notably, echocardiography is the technique with the greatest potential to raise the suspicion of AC by detecting specific signs (‘red-flags’) of cardiac infiltration. However, the epidemiology of the echocardiographic red-flags of AC n the general population of patients referred to echocardiography without clinical suspicion of AC and their diagnostic accuracy remain unknown. This is a national, multicentre, prospective cohort study performed in 13 tertiary centres across Italy. The local Regional Institutional Review Board approved the study (identifier 199_2019), and the participating centres obtained local institutional review board approvals for the collection of prospective anonymous data. The study was registered at ClinicalTrials.gov (#NCT04738266). The study design consisted of two phases: (i) an observational phase (echocardiographic screening) and (ii) an interventional phase (specific diagnostic work-up for patients with >_1 echocardiographic red-flags of AC). In this article, we present the study design and the results of phase 1. Phase 2 is ongoing.