QTc interval prolongation as a marker of disease stage in transthyretin cardiac amyloidosis.

Transthyretin amyloidosis is a significant cause of heart failure with an unfavorable prognosis. In recent years, diagnosing the disease has become easier, with most patients now diagnosed non-invasively, and tissue biopsy being required only in a minority of cases. Although various laboratory findings have been reported as transthyretin amyloidosis red flags, the diagnostic and prognostic value of various electrocardiogram parameters remain largely unknown. In this study, the significance of QTc interval prolongation in transthyretin cardiac amyloidosis patients was investigated. We retrospectively analyzed electrocardiogram data from n = 58 patients with transthyretin amyloid cardiomyopathy and compared them with distinct cohorts of patients diagnosed with other forms of heart muscle disease, i.e., hypertrophic cardiomyopathy and dilated cardiomyopathy. QTc prolongation was found to be a unique feature of transthyretin cardiac amyloidosis, not shared by other cardiomyopathy types. Increased QTc interval in transthyretin amyloidosis patients correlates with disease severity markers, including NYHA class, NAC stage, NT-proBNP, and troponin I levels, suggesting its potential as a unique biomarker for monitoring disease progression.