Wild-type transthyretin cardiac amyloidosis in a 56-year-old patient: A case report

Transthyretin (ATTR) amyloidosis is a progressive disease that can present as isolated cardiac involvement or as a combination with systemic manifestations, including polyneuropathy, gastrointestinal tract disorders, and ophthalmopathy. The disease is associated with the deposition of unstable breakdown products of transthyretin tetramers, a plasma protein responsible for transporting thyroxine and retinol. ATTR is most commonly hereditary (ATTRm/ATTRv), caused by mutations in the transthyretin gene, but it can also occur in an acquired, non-hereditary “wild-type” form (ATTRwt), which develops in older adults. Cardiac involvement in ATTR amyloidosis resembles hypertrophic or restrictive cardiomyopathy, manifesting as symptoms of heart failure, rhythm disorders, and conduction abnormalities. Diagnosis is challenging due to the rarity of the disease, nonspecific symptoms, and the difficulties of performing endomyocardial biopsy. The verification of the diagnosis increasingly relies on modern imaging methods such as gadolinium-enhanced magnetic resonance imaging and technetium-99m pyrophosphate myocardial scintigraphy. The presented clinical case describes a 56-year-old patient with amyloid cardiomyopathy, which manifested as a combination of progressive rhythm and conduction disturbances (atrial fibrillation, trifascicular block, pauses up to 4,7 seconds, and runs of ventricular tachycardia) against the background of gradually decreasing left ventricular ejection fraction and marked diastolic dysfunction. These clinical syndromes necessitated the exclusion of secondary causes of myocardial involvement. The diagnosis was confirmed without biopsy – through the use of modern imaging techniques, including contrast-enhanced cardiac MRI and 99mTc-pyrophosphate scintigraphy, in accordance with current recommendations. This case illustrates the possibility of early detection and successful treatment of ATTRwt amyloidosis using advanced diagnostic methods in real-world clinical practice. These methods help refine the disease’s prevalence, improve diagnostic accuracy, and ensure timely treatment, significantly influencing the prognosis and quality of life.

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