THE RELATIONSHIP BETWEEN CENTRAL AORTIC PRESSURE, BRACHIAL BLOOD PRESSURE AND LEFT VENTRICULAR MASS INDEX: IN FIRST DIAGNOSED HYPERTENSIVE PATIENTS: PP.29.164

Abstract

Background: Central (aortic) blood pressure (BP) has been reported as a more powerful indicator to predict cardiovascular risk than peripheral (brarchial) BP. Also, increased left ventricular mass index (LVMI) and its change during treatment can predict cardiovascular complications in hypertensive subjects. However, the relationship between aortic or peripheral BP and LVMI is not clear especially in first diagnosed hypertensive subjects. We purposed to compare the relationship of LVMI with central and peripheral BP parameters. Methods: We studied 111 patients who diagnosed hypertension for the first time without any medical history including diabetes (mean age: 47 ± 10 years, 72 males). Subjects with heart failure, any significant valvular disease or cardiomyopathy on echocardiogram were excluded. Peripheral BP was measured by automatic sphygmomanometer at brachial artery and central BP was measured by analysis of non-invasive radial artery pulse wave using automated applanation tonometry. The LVMI was calculated from M-mode echocardiographic data and body surface area. To avoid multiple co-linearity among BP parameters, multiple regressions predicting LVMI were done four times. Results: Baseline central and peripheral systolic BP (SBP) were 136 ± 17 and 150 ± 18mmHg (p < 0.001) and each mean pulse pressure (PP) was 41 ± 11 and 53 ± 13 mmHg respectively (p < 0.001). Mean PP difference was 11.7 ± 12.0 mmHg and mean LVMI was 109 ± 22 g. The LVMI was positively correlated with age, peripheral SBP & PP, central SBP & PP, and carotid intima-media thickeness (r = 0.231, 0.276, 0.283, 0.248, 0.343, 0.259 respectively, each p < 0.05). But, PP difference was not significantly correlated (p = 0.915). Although central and peripheral systolic and pulse pressures were still significantly related to LVMI after adjustment for age in the four different analyses, central PP was stronger predictor than peripheral PP (β coefficient = 0.311, p = 0.001 vs. 0.281, p = 003). Conclusion: Left ventricular mass index, which is one of useful indicators for predict cardiovascular risk and outcome of hypertension, is independently and positively associated with blood pressure parameters. Central pulse pressure is particularly more strongly related with LVMI than peripheral BP parameters.