Risk stratification in hypertension: NT-proBNP and R wave in aVL lead combination better than echocardiographic left ventricular mass.

Abstract

Plasma N-terminal pro brain natriuretic peptide (NT-proBNP) and R wave in aVL lead (RaVL) have been associated with mortality in hypertension. The aim of the current study was to compare the prognostic value of their combination to that of the left ventricular mass index (LVMI) assessed by echocardiography. A total of 1104 hypertensive patients who had at baseline an assessment of plasma NT-proBNP, a 12-lead ECG, and echocardiography were included. LVMI was assessable in 921 patients. After a median (interquartile range) follow-up of 8.5 (5.4-13.3) years, 110 deaths occurred, 62 of which were from a cardiovascular cause. Optimal thresholds of RaVL and plasma NT-proBNP to predict mortality were 0.7 mV and 150 pg/ml, respectively. A three-modality variable based on RaVL and NT-proBNP was built: 0 when none were above the threshold, 1 or 2 when only one or both were above the threshold. After adjustment for all confounders including LVMI indexed to height raised to the allometric power of 2.7 in Cox regression analysis, we observed a significant increased risk for patients having one marker above the threshold for all-cause and cardiovascular mortality [hazard ratio: 1.76; 95% confidence interval (1.08-2.86); 2.18 (1.06-4.46)] and for those having two markers above the threshold [2.76 (1.51-5.03); 3.90 (1.69-9.00)]. The prognostic value of the combination had the highest C-index (0.772 and 0.839, respectively) in comparison with LVMI (0.746 and 0.806, respectively). Risk stratification in hypertension using the combination of NT-proBNP and RaVL is a simple method that may be considered in first line screening.