Japanese cardiologists described a diagnosis pathway for transthyretin amyloidosis cardiomyopathy, or ATTR-CM, with uneven awareness outside heart-failure and cardiomyopathy services. They also described referrals that rarely cross specialty boundaries and geographically and institutionally limited access to the scans and other tests used in diagnosis.
The findings come from five cardiologists with ATTR-CM expertise working at tertiary-care centers. The paper says thematic saturation was not formally assessed, so the findings are exploratory and should not be treated as representative of ATTR-CM care across Japan.
Where patients can lose time
The clinicians saw a difference in how people enter the healthcare system. Cardiac presentations were perceived to reach cardiology more quickly, while patients whose first problems were outside the heart, including carpal tunnel syndrome, could face delays before ATTR-CM was considered.
Referral activity was described as concentrated within cardiology or specialist centers. Orthopedic and other non-cardiology services were seen as making relatively few referrals across specialties.
Participants linked reduced engagement in diagnosis or testing with limited understanding, travel burden, complex referral steps and stigma around genetic disease.
Testing is not the only hurdle
Access to scintigraphy, cardiac magnetic resonance imaging, biopsy and genetic testing was described as geographically and institutionally limited. Scintigraphy interpretation was also identified as a major bottleneck.
Awareness varied by specialty. The cardiologists perceived it as strongest among heart-failure and cardiomyopathy specialists and lower or less consistent elsewhere. They likewise described variation in treatment decision-making, suggesting that the challenge is not confined to finding the right test.
The authors discuss removal of a biopsy requirement as relevant to some barriers, but identify awareness, referral, imaging access and interpretation as potential remaining bottlenecks. The interviews took place before the policy change, so its post-change consequences were not observed.
A pathway built from guidance and interviews
Researchers used a mixed-methods approach to build an evidenced ATTR-CM care pathway for Japan. They first extracted steps from guidance, then arranged them into a sequence of care, and finally used a draft pathway in interviews to identify deviations, practice variation and bottlenecks. The pathway was organized around four patient-interaction stages: prediagnosis, diagnosis, relevant family screening and clinical management.
The interview group included three cardiologists from JCS-certified hospitals and two from non-JCS-certified hospitals. All were selected because they were actively involved in ATTR-CM care at tertiary centers. Researchers analyzed the transcripts in NVivo version 13 using deductive and inductive coding, with a second researcher reviewing the coding and themes until agreement.
What the evidence can answer
The small, cardiologist-only sample and the absence of non-cardiology interviewees mean that findings on awareness and referral outside cardiology are perception-based and not representative of all ATTR-CM care in Japan. The paper also says thematic saturation was not formally assessed.
AstraZeneca funded the study. Its employees H.T. and K.S. contributed to manuscript review and interpretation, but not to the interviews, primary coding or initial theme development. The paper also reports financial relationships for T.K. and J.E., while E.C. and Y.H. reported no conflicts.
Paper data and sources
Original title: Optimizing Diagnosis of Transthyretin Amyloidosis Cardiomyopathy in Japan : Care Pathway Barriers and Opportunities
Authors: Endo J, Kubo T, Suzuki K et al.
Journal/Repository: Circulation reports
Status: Peer-reviewed
First online: 2026-10-10
DOI: Not available
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