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BNP for Cardiac Amyloid

Cardiac involvement is the most important prognostic factor in immunoglobulin light chain amyloidosis (AL amyloidosis). Early identification of patients with cardiac amyloidosis allows for more aggressive chemotherapeutic treatment with proteasome inhibitors. The original Mayo cardiac staging system from 2004 relied on NT-proBNP as a biomarker for cardiac involvement. This biomarker limited the usefulness of this staging system because NT-proBNP is not as widely available as BNP.

The original Mayo staging system used a NT-proBNP level of 332 pg/mL as the threshold for cardiac amyloidosis. A recent study by Boston University established that a BNP level of 81 pg/mL was equivalent to a NT-proBNP level of 332 pg/mL. Using more modern cardiac imaging, they determined that a BNP level of 81 pg/mL and a NT-proBNP level of 288 pg/mL was predictive of light chain cardiac deposition.

Cardiac AL Stage BNP (pg/mL) TnI (ng/mL) eGFR
1 23-57 (36) 0.006-0.020 (0.011) 54-99 (84)
2 130-410 (210) 0.018-0.062 (0.035) 39-87 (64)
3 394-1401 (719) 0.138-0.399 (0.218) 33-80 (56)


The Boston University study suggested that BNP may be superior in predicting cardiac involvement in patients with chronic kidney disease stage (CKD) III or higher and that NT-proBNP may be more sensitive in patients with CKD stage II or lower. Different thresholds for cardiac amyloidosis must be used in patients with CKD: 427 pg/mL for BNP and 2930 pg/mL for NT-proBNP.

This study demonstrated that either BNP or NT-proBNP can now be used to initially test patients for cardiac amyloidosis. Patients with elevated values can then undergo more extensive workups.


Lilleness B. et al. Development and validation of a survival staging system incorporating BNP in patients with light chain amyloidosis. Blood 2019;133(3):215-223.

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