The impossible quest to make cardiac amyloidosis diagnosis easy

Cardiac amyloidosis (CA) is an increasingly recognized myocardial infiltrative disease, causing pseudo-hypertrophy of the heart, diastolic dysfunction and heart failure. Growing efforts are ongoing to optimize screening and diagnostic algorithms for CA [1]. This is motivated by the surfacing of targeted therapies, which are supposed to be more effective the earlier the diagnosis of CA is made [2]. Echocardiography represents a fundamental methodology for the clinician to trigger the suspicion of CA [3]. Although echocardiography serves as a gatekeeper to CA diagnosis, features such as left ventricular hypertrophy (LVH) or diastolic dysfunction, which are common in CA, are frequently encountered in other more prevalent cardiovascular conditions within the ample spectrum of hypertrophic phenocopies [4,5], thus making differential diagnosis difficult. To this end, the work published by Aimo and colleagues in this issue of the European Journal of Clinical Investigation aims at simplifying the process by which a suspect of CA might be confirmed or refuted through the sole echocardiographic examination [6]. The present analysis builds on a previous recent work by the same Authors and others [7], in which two scores named "AL score" and "IWT score" were developed using differently weighted echocardiographic variables (i.e., relative wall thickness - RWT, E wave/e' wave ratio - E/e', tricuspid annular plane systolic excursion, longitudinal strain and septal longitudinal systolic apex-to-base ratio). Those scores were showed to allow a correct diagnosis of CA, respectively among patients with proven systemic light-chain amyloidosis and with unexplained LVH [7]. In the present analysis, a simplified score named "AMYLI score" is proposed, obtained by just multiplying RWT by E /e'. This new score is shown to have particularly good performance in ruling-out a diagnosis of CA when a value <2.2 is found in patients referred by hematologists and <2.36 in patients with unexplained LVH [6]. The AMYLI score is thus presented as a clinically helpful tool to this end. However, some shortcomings of the present work - and more in general, of the imaging-centric diagnostic approach to CA - should be acknowledged and deserve some discussion.