Long-Term Effect of Tafamidis on Clinical Parameters and Prognostic Predictors in Patients With Transthyretin Amyloid Cardiomyopathy

Abstract

Background: Accurate prediction of prognosis in transthyretin amyloid cardiomyopathy (ATTR-CM) is crucial for optimal treatment selection, including tafamidis, the only approved therapy for ATTR-CM. Although tafamidis has been proven to improve prognosis, the long-term serial changes in comprehensive parameters related to ATTR-CM, including cardiac biomarkers and imaging parameters, under tafamidis remain unknown.

Methods and Results: In this study, we used Cox regression analysis on data from 258 consecutive patients diagnosed with ATTR-CM at Kumamoto University to determine prognostic factors. During clinical follow-up, the serial changes in parameters were compared between tafamidis-treated and tafamidis-naïve patients. An elevated high-sensitivity cardiac troponin T (hs-cTnT) level at baseline was identified as a stronger independent predictor of all-cause death compared with left ventricular ejection fraction (LVEF) and extracellular volume. During follow-up (median: 24.4 months), estimated glomerular filtration rate and LVEF declined significantly with time in both cohorts. Notably, serum hs-cTnT and B-type natriuretic peptide levels were significantly elevated in the tafamidis-naïve cohort compared to baseline, but this increase was prevented by tafamidis treatment.

Conclusions: Of the ATTR-CM-related parameters investigated, an increased hs-cTnT level at baseline was a promising determinant of poor prognosis. Long-term tafamidis treatment prevented a deterioration in cardiac biomarkers, and the measurement of these markers may enable appropriate monitoring of disease progression.