Higher visit-to-visit blood pressure variability and N-terminal pro-brain natriuretic peptide elevation: influence of left ventricular hypertrophy and left ventricular diastolic function

Abstract

The issue of whether visit-to-visit blood pressure variability (VVV) is associated with higher levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) has been controversial, and the underlying mechanism is not well understood. We hypothesized that (1) VVV is associated with the NT-proBNP level, and (2) this association is mediated by left ventricular (LV) hypertrophy and LV diastolic dysfunction. A total of 72 hypertensive patients were examined. Clinic blood pressure was measured at each visit for 12 months (1×/month or every 2 months), and echocardiography was performed during this period. VVV is expressed as the SD, coefficient of variation (CV), and delta (Δ; the difference between the maximum and the minimum) in SBP and in DBP. We investigated the association between VVV and NT-proBNP and whether the LV mass index (LVMI) and the mitral early diastolic inflow velocity (E) to mitral annular early-diastolic peak velocity (e') ratio (E/e') influence this association. The loge NT-proBNP values were significantly correlated with the CV of SBP (r = 0.42), ΔSBP (r = 0.41), the CV of DBP (r = 0.32), and ΔDBP (r = 0.28). The CV and Δ in SBP or those in DBP were not significantly correlated with LVMI or E/e'. A multiple linear regression analysis revealed that higher CV of SBP and ΔSBP were significantly associated with loge NT-proBNP. Higher VVV was significantly associated with higher NT-proBNP independently of LV hypertrophy and diastolic function.