Wild-Type Transthyretin Cardiac Amyloidosis with Multiple Organs Involvement: Case Report and a Brief Review of the Literature

Wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) is a progressive, underdiagnosed, and lethal restrictive cardiomyopathy, which is gaining more recognition as a heart failure with preserved ejection fraction (HFpEF) cause in the elderly. The diagnosis is challenging because this condition occurs without distinctive manifestations.  Older methods of diagnostic intervention were mainly based on invasive endomyocardial biopsy. This paper provides the case of a 66-year-old male with progressive dyspnea, a bilateral carpal tunnel syndrome history, with echocardiographic findings of concentric left ventricular hypertrophy with apical sparing strain pattern. Diagnosis was made without the use of invasive methods: a positive Technetium-99m PYP scintigraphy (Grade 3 uptake) and a rule out of monoclonal gammopathy, which were later confirmed by endomyocardial biopsy and mass spectrometry.

This case illustrates the importance of identifying non-cardiac warning signs and utilizing a streamlined diagnostic algorithm to achieve early and accurate subtyping. Following the necessary evaluations by a multidisciplinary team, the patient was diagnosed with Stage II ATTRwt-CA disease and started undergoing disease-modifying therapy, Tafamidis meglumine, in conjunction with optimized heart failure management. The patient clinical course had been stable over the last two years, which determines the significance of timely and accurate diagnosis and the introduction of effective treatment in altering the natural history of ATTRwt-CA. This report can be used to raise the awareness of clinicians about the contemporary diagnostic pathway and therapeutic imperative of this challenging condition.