Change in N-terminal pro-B-type natriuretic peptide at 1 year predicts mortality in wild-type transthyretin amyloid cardiomyopathy

Abstract

Objectives: Wild-type transthyretin amyloid cardiomyopathy (wtATTR-CM) is a progressive and fatal condition. Although prognosis can be determined at the time of diagnosis according to National Amyloidosis Centre (NAC) transthyretin amyloidosis (ATTR) stage, the clinical course varies substantially between individuals. There are currently no established measures of rate of disease progression. Through systematic analysis of functional, biochemical and echocardiographic disease-related variables we aimed to identify prognostic markers of disease progression in wtATTR-CM.

Methods: This is a retrospective observational study of 432 patients with wtATTR-CM diagnosed at the UK NAC, none of whom received disease-modifying therapy. The association between mortality from the 12-month timepoint and change from diagnosis to 12 months in a variety of disease-related variables was explored using Cox regression.

Results: Change in N-terminal pro-B-type natriuretic peptide concentration (∆ NT-proBNP) at 12 months from diagnosis was the strongest predictor of ongoing mortality and was independent of both change in other disease-related variables (HR 1.04 per 500 ng/L increase (95% CI 1.01 to 1.07); p=0.003) and a range of known prognostic variables at the time of diagnosis (HR 1.07 per 500 ng/L increase (95% CI 1.02 to 1.13); p=0.007). An increase in NT-proBNP of >500 ng/L, >1000 ng/L and >2000 ng/L during the first year of follow-up occurred in 45%, 35% and 16% of patients, respectively.

Conclusion: Change in NT-proBNP concentration during the first year of follow-up is a powerful independent predictor of mortality in wtATTR-CM.

Keywords: biomarkers; cardiomyopathies; heart failure.

Figure 1

Landmark Kaplan-Meier survival curves stratified by ∆ NT-proBNP during the first year of follow-up. Numbers at risk are shown below each curve. (A) Patient survival stratified by ∆ NT-proBNP >500 ng/L or ≤500 ng/L (HR 1.65 (95% CI 1.18 to 2.31); p=0.003). (B) Patient survival stratified by ∆ NT-proBNP >1000 ng/L or ≤1000 ng/L (HR 1.92 (95% CI 1.37 to 2.70); p<0.001). (C) Patient survival stratified by ∆ NT-proBNP >2000 ng/L or ≤2000 ng/L (HR 2.87 (95% CI 1.93 to 4.27); p<0.001). NT-proBNP, N-terminal pro-B-type natriuretic peptide.