Use of B-type natriuretic peptide to predict blood pressure improvement after percutaneous revascularisation for renal artery stenosis.

Abstract

The purpose of this study was to evaluate the utility of B-type natriuretic peptide (BNP) to predict blood pressure (BP) response in patients with renal artery stenosis (RAS) after renal angioplasty and stenting (PTRA). In 120 patients with RAS and hypertension referred for PTRA, 24-h ambulatory BP recordings were obtained before and 6 months after intervention. BNP was measured before, 1 day and 6 months after PTRA. BP improved in 54% of patients. Median BNP levels pre-intervention were 97 pg ml(-1) (interquartile range (IQR) 35-250) and decreased significantly within 1 day of PTRA to 62 pg ml(-1) (IQR 24-182) (p < 0.001), remaining at 75 pg ml(-1) (IQR 31-190) at 6 months. The area under the receiver operating curve for pre-intervention BNP to predict BP improvement was 0.57 (95% confidence interval (CI) 0.46-0.67). Pre-intervention BNP >50 pg ml(-1) was seen in 79% of patients with BP improvement compared with 56% in patients without improvement (p = 0.01). In a multivariate logistic regression analysis, BNP >50 pg ml(-1) was significantly associated with BP improvement (odds ratio (OR) 4.0, 95% CI 1.2-13.2). BNP levels are elevated in patients with RAS and decrease after revascularisation. Although BNP does not seem useful as a continuous variable, pre-interventional BNP >50 pg ml(-1) may be helpful to identify patients in whom PTRA will improve BP.