Wild-type transthyretin cardiac amyloidosis: a case of multisystemic involvement and review of literature

Introduction: Cardiac amyloidosis (CA) represents a progressively evolving infiltrative pathology, defined by the myocardial accumulation of amyloid fibrils. The condition predominantly originates from transthyretin-derived (ATTR) or immunoglobulin light chain-related (AL) amyloidosis. ATTR cardiomyopathy (ATTR-CM), particularly the wild-type (wt) form (wtATTR-CM), is becoming more widely acknowledged as a contributor to cardiac dysfunction in the elderly population. However, diagnosing ATTR-CM remains challenging due to its clinical similarity to other cardiac conditions and a history of frequent misdiagnoses. Recent advancements in nuclear imaging using bone-avid radiotracers have greatly improved the ability to diagnose ATTR-CM non-invasively. Case presentation: This case involves an 86-year-old male with documented peripheral joint disease, supraspinatus tendon rupture affecting both limbs, referred for exertional dyspnea. Echocardiography indicated left ventricular hypertrophy, diastolic dysfunction, reduced global longitudinal strain, accompanied by severe mitral regurgitation (MR) secondary to prolapse of the posterior mitral leaflet. Cardiac magnetic resonance (CMR) imaging revealed concentric hypertrophy, elevated T1 mapping, and increased extracellular volume, highly suggestive of amyloid deposition. Bone scintigraphy confirmed the diagnosis of ATTR-CM with a Perugini score of 3. A biopsy of the abdominal fat pad revealed amyloid deposits. Conclusions: Such presentations of ATTR-CM emphasize its systemic nature and the need for early recognition and treatment. An important aspect of this case is the uncommon association between CA and posterior mitral valve prolapse, which leads to significant MR.