Background: 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.
Methods: 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.
Results: 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).
Conclusion: 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.