NAC / Gillmore Stage (Transthyretin Cardiac Amyloidosis)
The NATIONAL AMYLOIDOSIS CENTRE (NAC / GILLMORE) STAGE for transthyretin cardiac amyloidosis (Gillmore and colleagues 2018; expanded by Nitsche and colleagues 2024), reported in BOTH versions.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- NT-proBNP in ng/L; pg/mL is numerically identical, so no conversion is needed
- 12000 ng/L
- eGFR
- 60 ml/min
Result: stage 4
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Stage 1
- NT-proBNP at or below 3000 ng/L AND eGFR at or above 45 ml/min. 1-year mortality 2.3%.
- Stage 2
- One criterion but not both. 1-year mortality 8.8%. LUMPS TOGETHER cardiac-dominant and renal-dominant patients.
- Stage 3
- NT-proBNP above 3000 AND eGFR below 45. 1-year mortality 10.4%; median survival 33.5 months.
- Stage 4
- 2024 expansion: NT-proBNP at or above 10,000 ng/L IRRESPECTIVE OF eGFR. 1-year mortality 30.6%; median 22.5 months.
- Cuts across
- Stage 4 is NOT a tail of stage 3. Of 180 stage 4 patients, 65 came from original stage 2 and 115 from stage 3.
- Overlap
- The published stage 2 definition is an OR that every stage 3 patient also satisfies. Stage 2 is applied as the residual.
- Cut-point
- Rounded from the Youden-optimal 10,461 ng/L; sensitivity about 54%. A stage below 4 is NOT reassurance.
- eGFR equation
- NOT stated in the source. CKD-EPI and MDRD disagree by several ml/min right at the 45 boundary.
- Median
- NULL for stages 1 and 2 on purpose - no median was reached within 36 months.
- Scope
- Stages an established diagnosis. Does not diagnose, does not separate ATTR from AL, does not select or withhold tafamidis.
What you enter
- NT-proBNP in ng/L; pg/mL is numerically identical, so no conversion is needed.
- eGFR.
Full field descriptions
- NT-proBNP in ng/L; pg/mL is numerically identical, so no conversion is needed. Above 3000 moves the original stage; at or above 10000 makes it stage 4 irrespective of eGFR.
- eGFR. Below 45 moves the original stage. THE SOURCE DOES NOT STATE WHICH EQUATION PRODUCED IT, and CKD-EPI and MDRD disagree by several ml/min right at this boundary.
How this is calculated
Gillmore JD, Damy T, Fontana M, et al. A new staging system for cardiac transthyretin amyloidosis. Eur Heart J. 2018;39(30):2799-2806. Expanded in Nitsche C, Patel RK, Hong Y, et al. Eur J Heart Fail. 2024;26(9):2008-2016. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.