Is elevation of N-terminal pro-B-type natriuretic peptide at discharge associated with 2-year composite endpoint of all-cause mortality and heart failure hospitalisation after transcatheter aortic valve implantation? Insights from a multicentre prospective OCEAN-TAVI registry in Japan

Objectives The aim of this study was to investigate the 2-year prognostic impact of N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels at discharge following transcatheter aortic valve implantation (TAVI). Design Multicentre prospective observational study. Settings Seven institutions from multicentre, observational registry of symptomatic patients with severe aortic stenosis who undergo TAVI. Participants We enrolled 500 consecutive patients who underwent TAVI with measurements of NT-proBNP at discharge between 2013 and 2016. Study patients were stratified into two groups according to survival classification and regression tree (CART) analysis: high versus low NT-proBNP groups. Interventions The impact of high NT-proBNP on a 2-year composite endpoint consisting of all-cause mortality and heart failure hospitalisation was evaluated using a multivariable Cox model. Results Median age was 86 years (quartile 82-89), and 24.2% of the study population were men. Median Society of Thoracic Surgeon score was 7.1 (5.1-9.8), and NT-proBNP at discharge was 1381 (653-3136) pg/mL. The composite endpoint incidence was 13.0% (95% CI 9.5% to 16.3%) at 1 year and 22.3% (95% CI 16.1%-27.9%) at 2 years. The survival CART analysis revealed that the NT-proBNP level required to discern the 2-year composite endpoint was 4288 pg/mL. Elevated NT-proBNP had a statistically significant impact on outcomes, with adjusted HR of 2.21 (95% CI 1.21 to 4.04, p=0.010), and with a significant sex difference (P for interaction=0.003). Conclusion Elevation of NT-proBNP at discharge is associated with higher incidence of the 2-year composite endpoint after TAVI.