Heart failure & cardiomyopathiesCohort study
Myocardial Amyloid Burden in Transthyretin Amyloidosis
- Cohort study
Authors' conclusion
ECV directly quantifies myocardial amyloid load and, for the first time, defines reproducible thresholds that stratify burden and refine risk prediction beyond stage, biomarkers, and imaging, providing a quantitative framework for staging and therapeutic planning in ATTR amyloidosis.
Study context
- Population
- Subjects undergoing cardiovascular magnetic resonance (CMR) for transthyretin amyloidosis (ATTR)
- Participants
- 123 / 41 / 70 / 1,308
- Exposure
- CMR-ECV categories in ATTR amyloidosis
- TTR-variant carriersn = 123
- Extracardiac ATTRn = 41
- Early-stage ATTR-CMn = 70
- Overt ATTR-CMn = 1,308
- Outcome
- All-cause mortality
- Follow-up
- Median 2.8 years (IQR: 1.4-4.3 years)
Main finding
As reported in the abstract
median 2.8 years
Hazard ratio
1.22
95% CI 1.10–1.34
P < 0.001
ECV (per 10% increase)
HR 1.22 (95% CI 1.10–1.34); P < 0.001
Per 10% increase, as printed
- Deaths
- 612 patients (40%)
Observational data: associations, not effects.
Further findings
Diagnostic thresholds for cardiac involvement
- Extracellular volume (ECV) <30% excluded cardiac involvement
- ECV ≥40% confirmed cardiac involvement
- ECV 30% to 39% indicated early infiltration
ECV by group
- ECV similar in carriers and extracardiac ATTR, rose from early-stage to ATTR-CM
Prognostic value across strata
- ECV retained prognostic value across hs-troponin and NT-proBNP strata, Perugini grades 1 to 3 and left ventricular mass index (LVMI) tertiles; steeper gradients in low-biomarker/low-LVMI strata
Parts of this Brief are withheld: the automatic checks could not confirm them against the abstract.
Original publication
Myocardial Amyloid Burden in Transthyretin Amyloidosis. J Am Coll Cardiol. Published 8 November 2025. doi:10.1016/j.jacc.2025.10.054
Summarised from the published abstract; every number is checked against it