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

ABSTRACT

OBJECTIVES: 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). METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.