Clinical Benefit of the Transthyretin Stabiliser Tafamidis in Hereditary Transthyretin Amyloid Cardiomyopathy: A Case Report.

Abstract

Aims/background: This case report aims to illustrate the critical importance of a standardized diagnostic approach and genotype-specific therapy in hereditary transthyretin amyloid cardiomyopathy (ATTR-CM). It highlights the clinical challenge of diagnosing ATTR-CM amidst complex comorbidities and addresses the evidence gap regarding the long-term efficacy of tafamidis for the rare and aggressive p.Val40Ile (protein-level substitution of valine to isoleucine at codon 40) mutation.

Case presentation: A 72-year-old East Asian man with multiple comorbidities presented with refractory heart failure. Key clinical clues included the classic "red flag" of electrocardiogram (ECG)-echocardiogram discordance (low voltage with ventricular hypertrophy). Genetic testing identified the pathogenic p.Val40Ile transthyretin (TTR) mutation.

Results: The diagnosis was confirmed non-invasively via cardiac magnetic resonance (CMR) and technetium-99m pyrophosphate scintigraphy. Following the initiation of tafamidis, the patient's symptoms significantly improved. Over a two-year follow-up period, he sustained clinical stability with a marked reduction in heart failure-related hospitalizations.

Conclusion: This report provides detailed case-based evidence supporting the long-term efficacy of tafamidis in stabilizing disease and improving prognosis for patients with ATTR-CM harboring the p.Val40Ile mutation. It underscores the value of timely diagnosis, genetic subtyping, and access to targeted therapy in altering the clinical course of this aggressive genotype.