Abnormal BNP in asymptomatic well controlled hypertensive subjects is a novel marker associated with early cardiovascular structural abnormalities, i.e. left ventricular hypertrophy

Abstract

Introduction: Measurement of B-type natriuretic peptide (BNP) or NT Pro-BNP has been advocated for cardiovascular disease (CVD) risk stratification. The purpose of this study is to assess the association between the presence of abnormal BNP/pro BNP and early detection of left ventricular hypertrophy (LVH) in asymptomatic hypertensive subjects with well controlled hypertension (HTN). Methods: We evaluated 2230 asymptomatic subjects aged 23-80 years, who underwent screening for CVD risk stratification using Early CVD Risk Score (ECVDRS), also known as Rasmussen Risk Score (RRS). ECVDRS consists of 10 non-invasive tests: large (C1) and small (C2) artery stiffness, blood pressure (BP) at rest and post mild exercise (PME), Carotid Intima Media Thickness (CIMT), abdominal aorta ultrasound, retinal photography, microalbuminuria, electrocardiogram (ECG), left ventricular ultrasound, and BNP/Pro-BNP. Results: Among the 2230 asymptomatic subjects, we analyzed 226 hypertensive subjects who are currently treated for HTN and are well controlled. To test the hypothesis that asymptomatic subjects with LVH have a significantly higher BNP/ProBNP values than those without LVH despite HTN control, we used a Chi-square tests to test the independence between patients with or without LVH regarding their BNP/ProBNP status coded as being normal or abnormal. The prevalence of LVH was 35% (n1⁄480) and the finding of the Chi-square test was highly significant; the proportion of abnormal LVH was 0.28 and 0.53 respectively with normal vs elevated BNP/ProBNP for the patients in our study, c; (1, N 1⁄4 226) 1⁄4 13.370, p 1⁄40.0004. Conclusions: Abnormal BNP/pro-BNP levels were significantly associated with echo-determined LVH in asymptomatic hypertensive subjects despite of having well controlled HTN. Based on these findings, we propose that measurement of ProBNP/BNP in hypertensive subjects can serve as a useful screening tool for further risk stratification and justify appropriate treatment and follow up to avert the progression of structural abnormality such as LVH, which is known to be associated with significant morbidity and mortality. ‘‘Prevention is better than cure’’.