Abstract 1620: Serum Levels of NT-proBNP in Patients with Cardiac Amyloidosis Correlate With Myocardial Mass and Late Gadolinium Enhancement as Assessed by Cardiac Magnetic Resonance Imaging
Background: Recently the prognostic value of n-terminal brain natriuretic peptide (NT-proBNP) has been recognized in pts with amyloid light chain (AL) or familial transthyretin (ATTR) amyloidosis complicated by cardiac involvement. Since the underlying mechanism for NT-proBNP release in cardiac amyloidosis is still unclear, we sought to use contrast enhanced cardiac MRI (CE-MRI) to identify functional and structural alterations related to NT-proBNP levels.
Methods and Results: CE- MRI was performed on a 1.5 T clinical scanner (Intera Achieva®, Philips Medical Systems) in 34 pts with biopsy proven AL (n= 27) or ATTR (n=7) amyloidosis. Levels of NT-proBNP measured at the time of MRI were higher in pts with (n= 25) compared to pts without cardiac involvement (n= 9) (2931(25–27277) ng/l vs. 177(22–7935) ng/L, p= 0.01). ROC analysis identified a NT-proBNP cut-off of 1900 ng/L as optimal discriminator for the occurrence of the combined endpoint of cardiac death, heart transplantation or ICD implantation during the follow-up period of 338± 38 days (Fig.1⇓) NT-proBNP levels did not correlate with left ventricular EF, EDV and ESV. However, there was a strong correlation between NT-proBNP and myocardial mass (R= 0.5, p= 0.005) and late gadolinium enhancement score (R= 0.46, p= 0.02) and an inverse relation to stroke volume (R= −0.4, p= 0.03).
Conclusions: The present study confirms the prognostic value of NT-proBNP in patients with AL and ATTR amyloidosis. While NT-proBNP levels had no relation to systolic function, a strong correlation could be found with measures of myocardial amyloid burden such as LV mass and delayed hyperenhancement.