Preliminary Real-World Evidence of Clinical and Echocardiographic Changes After Vutrisiran Initiation in Patients With Variant Transthyretin Amyloid Cardiomyopathy in Non-Endemic Regions: A Single-Center Observational Study

Background

Real-world data describing the clinical course after vutrisiran initiation in patients with variant transthyretin amyloid cardiomyopathy (ATTRv-CM) in non-endemic regions remain limited, particularly in Asian cohorts and in patients transitioning from patisiran. We evaluated preliminary real-world changes after vutrisiran initiation in patients with ATTRv-CM. Methods and results: This single-center retrospective observational study included 18 patients with ATTRv-CM from the Oita-ATTR-CM cohort. Ten patients who initiated small interfering RNA therapy with vutrisiran were classified as the vutrisiran-naive group, and 8 patients who switched from patisiran to vutrisiran were classified as the vutrisiran-switch group. Changes in transthyretin (TTR), N-terminal pro B-type natriuretic peptide (NT-proBNP), troponin T, and echocardiographic parameters from baseline to 1 year were descriptively evaluated. Vutrisiran markedly reduced TTR in both groups. NT-proBNP significantly decreased in both groups, and troponin T decreased only in the vutrisiran-naive group. E/e' significantly decreased in both groups, whereas left ventricular ejection fraction, interventricular septal thickness, and left ventricular mass remained largely unchanged. During follow up, 2 patients were hospitalized for heart failure and 1 died of a non-cardiovascular cause; all events occurred in the vutrisiran-switch group.