A simple staging system using biomarkers for wild‐type transthyretin amyloid cardiomyopathy in Japan

Aims It has been reported that a staging system combining N‐terminal pro‐B‐type natriuretic peptide and high‐sensitivity troponin T (hs‐cTnT) or estimated glomerular filtration rate (eGFR) is useful in patients with wild‐type transthyretin amyloid cardiomyopathy (ATTRwt‐CM). However, these studies were mainly conducted in Western countries, and their usefulness for the Japanese population is unclear. We examined and validated the staging system using hs‐cTnT, eGFR, and B‐type natriuretic peptide (BNP) in Japanese patients with ATTRwt‐CM. Methods and results We retrospectively evaluated 176 patients with ATTRwt‐CM. The cut‐off values of hs‐cTnT and eGFR were selected as 0.05 ng/mL and 45 mL/min/1.73 m2, respectively, based on a previous report. The optimal cut‐off value of BNP was 255.6 pg/mL to predict all‐cause mortality (sensitivity, 75%; specificity, 58%; area under the curve, 0.69; 95% confidence interval [CI], 0.61–0.78; P 0.05 ng/mL) and BNP (>250 pg/mL) and decreased eGFR (