Background: Twenty-four-hour blood pressure (BP) variability is an important predictor of organ damage and cardiovascular events. Although epidemiological data are widely based on evaluation of office (clinic) BP, 24-hour ambulatory BP monitoring (ABPM) accurately assess the severity of hypertension to predict cardiovascular events in hypertensive patients, because it more accurately reflects BP load on heart and blood vessels. Conventional transthoracic echocardiography (TTE), such as M-mode and two-dimensional (2D), and more advanced techniques, such as tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE), are used to identify pathological changes of the hypertensive heart disease. In addition, the study of systemic arterial compliance (SAC) predicts the impact of the arterial stiffness on the LV remodeling.
Methods: Fifty-eight patients (34 males and 24 females, aged 53±12 years) with hypertension for at least one year were studied using Ambulatory Blood Pressure Monitoring (ABPM), with evaluation of 24-hour, day time, night time and sleep and awake average systolic and diastolic BP, and subsequently with TTE, to evaluate the influence of the 24-hour average BP, integrated with echocardiographic parameters, on cardiovascular adaptations in hypertensive patients. ECHO parameters examined were: left ventricle (LV) mass indexed to body surface area (LVMi), LV ejection fraction (EF), left atrial volume indexed to body surface area (LAVi), mitral inflow velocities (E, A and E/A), mitral annulus velocities (S' and E') and E/E' ratio by TDI, LV global longitudinal strain (GLS) using 2D STE. SAC was derived by the ratio SVi/PP, using echocardiographic stroke volume index to body surface area (SVi) and pulse pressure (PP).
Results: LVMi showed a correlation with the 24-hour average BP (SBP r=0.32; DBP r=0.26), SBPd (r=0.32), DBPd (r=0.28) and SBPn (r=0.29). GLS was correlated with the 24-hour average BP (SBP r=0.30; DBP r=0.32), SBPd (r=0.32), DBPd (r=0.32) and with LVMi (r=0.42), LAVi with 24 hour SBP (r=0.28), while SAC with LVMi (r=0.29) and LAVi (r=0.33).
Conclusions: ABPM and TTE evaluation can be particularly useful in hypertensive patients, even with normal office BP, to highlight the influence of 24-hour blood pressure profile on LVM, and to a lesser extent, on LAV. SAC, instead, seems to be correlated both to LVM and LAV, independently of BP levels.