Cardiac involvement is the principal determinant of prognosis in light-chain (AL) amyloidosis. B-type natriuretic peptide (BNP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) are central for diagnosis, risk stratification, and response assessment.1,2 However, the use of BNP or NT-proBNP varies across institutions and clinical trials, complicating application and comparison of staging systems. Prior studies in the general heart failure populations have proposed conversion formulas between NT-proBNP and BNP,3,4 demonstrating variable performance, especially at the higher-value ranges and in the presence of renal dysfunction. The unique pathophysiology and frequent renal dysfunction in AL amyloidosis underscore the need for a disease-specific conversion tool.
