N-terminal brain natriuretic peptide predicted cardiovascular events stronger than high-sensitivity C-reactive protein in hypertension: a LIFE substudy

Abstract

N-terminal pro-brain natriuretic peptide (Nt-proBNP) and high-sensitivity C-reactive protein (hsCRP) are cardiovascular risk markers in various populations, but are not well examined in hypertension. Therefore, we wanted to investigate whether high Nt-proBNP or hsCRP predicted the composite endpoint of cardiovascular death, non-fatal stroke or non-fatal myocardial infarction independently of traditional cardiovascular risk factors and the urine albumin: creatinine ratio (UACR), which is a well established cardiovascular risk factor in hypertension. In 945 hypertensive patients from the LIFE study with electrocardiographic left ventricular (LV) hypertrophy, we measured traditional cardiovascular risk factors including electrocardiography, morning UACR, hsCRP by immunoturbidimetry assay and Nt-proBNP by immunoassay after 2 weeks of placebo treatment. During 55 months' follow-up 80 patients suffered a composite endpoint. HsCRP as well as Nt-proBNP above the median values of 3.0 mg/l and 170 pg/ml, respectively, was associated with a higher incidence of composite endpoint (13.1 versus 3.8%, P < 0.01, and 11.5 versus 5.4%, P < 0.01). In Cox regression analyses, standardized log(hsCRP)/SD predicted a composite endpoint [hazard ratio (HR) 1.3 per SD = 0.47 log(mg/l), P < 0.05] after adjustment for traditional cardiovascular risk factors, but not after further adjustment for UACR. Standardized log(Nt-proBNP)/SD predicted a composite endpoint after adjustment for traditional cardiovascular risk factors [HR 1.9 per SD = 0.49 log(pg/ml), P < 0.05] as well as after further adjustment for UACR [HR 1.5 per SD = 0.49 log(pg/ml), P < 0.01]. Log(Nt-proBNP) added significantly to the Cox regression models using traditional cardiovascular risk factors with and without UACR (both P < 0.001). Nt-proBNP predicted a composite endpoint after adjustment for traditional risk factors, UACR and a history of diabetes or cardiovascular disease and added significantly to the prediction of composite endpoint, whereas hsCRP did not.