Drachman, Brian

Background: Atrial fibrillation (AF) significantly impacts quality of life (QoL) and is often observed in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). Acoramidis achieves near-complete (≥90%) transthyretin (TTR) stabilization and is approved in the USA, the UK, Europe and Japan for the treatment of ATTR-CM in adults. In the phase 3 ATTRibute-CM study (NCT03860935), acoramidis treatment significantly reduced the time to all-cause mortality (ACM) or first cardiovascular-related hospitalization (CVH) at Month 30, and resulted in improved 6-minute walk distance (6MWD), Kansas City Cardiomyopathy Questionnaire-Overall Summary (KCCQ-OS) scores and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels relative to placebo. The clinical efficacy of acoramidis has not yet been reported in patients with ATTR-CM and with an AF or atrial flutter (AFL) diagnosis at baseline. Research Question: How does acoramidis treatment affect ACM or first CVH, 6MWD, KCCQ-OS scores, and NT-proBNP levels at Month 30 in participants with ATTR-CM with or without AF/AFL diagnosis at baseline? Methods: The ATTRibute-CM study design has been previously published. This post hoc analysis included participants in the modified intention-to-treat population (N=611) grouped by AF/AFL diagnosis at baseline (defined as recorded AF medical history or the presence of AF or AFL on an ECG at enrollment). The rate of ACM or first CVH at Month 30 was compared between groups using a stratified Cox proportional hazards model. Changes from baseline to Month 30 in 6MWD, KCCQ-OS scores and NT-proBNP levels were summarized descriptively. Results: Overall, 62.8% (384/611) of participants had an AF/AFL diagnosis at baseline (acoramidis: 255/409, placebo: 129/202). These participants had lower mean 6MWD and KCCQ-OS scores and higher median NT-proBNP levels than those without AF/AFL diagnosis at baseline. Treatment with acoramidis reduced ACM or first CVH, slowed the decline in 6MWD and KCCQ-OS scores and blunted the rise in NT-proBNP compared with placebo, regardless of AF/AFL diagnosis at baseline ( Table ). Conclusions: Acoramidis improved clinical outcomes (ACM, CVH), functional status, QoL and NT-proBNP levels relative to placebo in participants with ATTR-CM, regardless of AF/AFL diagnosis at baseline.

Cardiomyopathy is a manifestation of transthyretin amyloidosis (ATTR), which is an underrecognized systemic disease whereby the transthyretin protein misfolds to form fibrils that deposit in various tissues and organs. ATTR amyloidosis is debilitating and associated with poor life expectancy, especially in those with cardiac dysfunction, but a variety of treatment options have recently become available. Considered a rare disease, ATTR amyloidosis may be more prevalent than thought, particularly in older persons. Diagnosis is often delayed because of a lack of disease awareness and the heterogeneity of symptoms at presentation. Given the recent availability of effective treatments, early recognition and diagnosis are especially critical because treatment is likely more effective earlier in the disease course. The Amyloidosis Research Consortium recently convened a group of experts in ATTR amyloidosis who, through an iterative process, agreed on best practices for suspicion, diagnosis, and characterization of disease. This review describes these consensus recommendations for ATTR associated with cardiomyopathy as a resource to aid cardiologists and others in the recognition and diagnosis of ATTR associated with cardiomyopathy. Included in this review is an overview of red flag signs and symptoms and a recommended diagnostic approach, including testing for monoclonal protein, scintigraphy, or biopsy and, if ATTR associated with cardiomyopathy is identified, TTR genotyping.