Objective: A nationwide survey on systemic wild-type ATTR (ATTRwt) amyloidosis was conducted to elucidate the frequency, clinical picture and possible diagnostic issues of ATTRwt amyloidosis in Japan.
Methods: A questionnaire was sent to 4629 clinical departments across Japan. A total of 2341 (50.6%) responses were returned completed for further analysis.
Results: Fifty-one patients with ATTRwt amyloidosis (82% male) were identified between January 2012 and December 2014. The study subjects were identified in 11 departments at 10 institutes. The mean age of onset and diagnosis were 71.6 and 73.6 years, respectively. The main clinical findings were cardiac failure (76%), cardiac conduction defects/arrhythmia (59%), renal dysfunction (49%), carpal tunnel syndrome (45%) and spinal canal stenosis (22%).
Conclusions: ATTRwt amyloidosis is diagnosed in a limited number of institutes in Japan and is therefore considered to be underdiagnosed.
Keywords: Wild-type ATTR amyloidosis; amyloid; nationwide survey; senile systemic amyloidosis; transthyretin.