Usefulness of plasma B-type natriuretic peptide as a prognostic marker of cardiac function in senile systemic amyloidosis and in familial amyloidotic polyneuropathy

Abstract

Objective: In senile systemic amyloidosis (SSA), a common age-related amyloidosis, wild-type transthyretin accumulates in tissues, with a primary result being cardiac dysfunction. Here, we aimed to clarify the usefulness of B-type natriuretic peptide (BNP) as a prognostic marker of cardiac function in SSA and in familial amyloidotic polyneuropathy (FAP).Methods and results: We studied 13 patients with severe SSA and 14 patients with FAP. SSA patients, but not FAP patients, demonstrated a significant correlation of log BNP with the echocardiographic diastolic marker E/e′ ratio (r = 0.78, p < 0.01). SSA patients also showed significant correlations between log BNP and log C-reactive protein or log high-sensitive troponin T (r = 0.70, p < 0.01; r = 0.64, p < 0.05). FAP patients, however, had significant correlations between log BNP and left ventricular wall thickness (intraventricular septum thickness diastole and posterior wall thickness diastole) (r = 0.73, p < 0.01; r = 0.77, p < 0.01). The mean log BNP level in the follow-up period was significantly higher than that in the diagnostic period in SSA patients (2.65 ± 0.45 versus 2.36 ± 0.40, p < 0.01) but not in FAP patients (1.91 ± 0.56 versus 1.93 ± 0.45, p = 0.87). An especially notable phenomenon was the high plasma BNP level (≥180 pg/ml) in SSA patients.Conclusion: Plasma BNP levels may be a useful prognostic marker of cardiac function in SSA.