B-type natriuretic peptide is associated with remodeling and exercise capacity after transcatheter aortic valve replacement for aortic stenosis

Abstract

Background: We aimed to assess longitudinal changes of B-type natriuretic peptide (BNP) in aortic stenosis (AS) patients treated by transcatheter aortic valve replacement (TAVR). Methods: From our TAVR database, we identified 193 consecutive patients with severe symptomatic AS who underwent TAVR and were prospectively followed using serial BNP levels and echocardiography. Patients were divided into subgroups according to type of left ventricular (LV) remodeling as having normal LV mass and relative wall thickness, or showing concentric remodeling (CR), concentric hypertrophy (CH), and eccentric hypertrophy (EH). Results: At baseline, 30 patients (16%) had EH, 115 (60%) had CH, 37 (19%) had CR, and 11 (6%) had normal LV geometry. After TAVR, BNP decreased in the first 30 days, with further improvement during follow-up. Patients with EH had higher BNP at baseline (P < 0.01) and a greater subsequent decrease (P < 0.001). During the median follow-up of 1331 days (interquartile range: 632-1678), 119 (62%) patients died. BNP showed a time-dependent association with all-cause mortality both in a univariable (hazards ratio [HR] 1.24, 95% confidence interval [CI]: 1.04-1.47, P = 0.017), and in a multivariable model with Society of Thoracic Surgeons score and baseline BNP forced into the analysis (HR 1.32, 95% CI: 1.001-1.73, P = 0.049). Elevated BNP was associated with a larger LV end-diastolic volume index (P < 0.001) and shorter 6-minute walk test distance (P = 0.013) throughout follow-up. Conclusion: In patients with AS, BNP was associated with LV remodeling phenotypes and functional status before and after TAVR. Elevated BNP levels were associated with poor prognosis.