P-42: Extent of nocturnal blood pressure decrease: Lack of impact on cardiovascular changes in never-treated essential hypertensives

The clinical significance of both the extent of nocturnal blood pressure (BP) fall and the resulting classification of hypertensives (H) as dipper (BP fall > 10% day BP) or non-dipper ( BP fall < 10% of day BP) has been questioned recently. Aim of our study was to evaluate in never-treated essential H if a blunted nocturnal BP fall influences the cardiovascular characteristics. We enrolled 208 never-treated essential H (mean 24-hour BP > 140 and/or 90 mmHg). For each patient we recorded: M-mode left ventricular (LV) echocardiogram, subsequently digitized, Doppler transmitral flow velocities and carotid-femoral pulse wave velocity,index of aortic distensibility. We evaluated: 24-hour, day-time, night-time systolic BP (SBP), diastolic BP (DBP) and heart rate (HR), % nocturnal fall of SBP and DBP (%fall), LV end-diastolic diameter (DD), end-diastolic septal (ST) and posterior wall thickness (WT), relative wall thickness (RWT), LV mass index (LVMi), peak shortening (-dD/dt) and lengthening rate (+dD/dt) of LV diameter, peak thinning rate of LV posterior wall (dW/dt), peak E and peak A transmitral flow velocity, E/A ratio, deceleration time of E wave (Dec E), isovolumic relaxation time (IRT), carotid-femoral pulse wave velocity (PWV). Out of the 208 H, 128 were dipper (D) and 80 were non-dipper (ND). Body mass index, gender, 24-hour, day-time and night-time HR, 24-hour and day-time BP were similar between D and ND. All LV morphological characteristics (DD, ST, WT, RWT and LVMi) were not significantly different between D and ND, as were peak A, Dec E and the M-mode indices of LV systolic (-dD/dt) and diastolic function (+dD/dt, dW/dt). The differences between D and ND with regard to peak E, E/A, IRT and PWV lost the statistical significance after adjustment for age. The extent of nocturnal BP fall did not correlate with LV parameters and with PWV in the 2 groups, neither evaluating the 208 H all together. In conclusion, in never treated H, the extent of nocturnal BP decrease, evaluated on the basis of one 24-hour BP monitoring, does not influence LV characteristics and aortic distensibility. (See Table) Age SBP%fall DBP%fall peak E E/A IRT PWV D 43 ± 9 15.7 ± 5.7 18.5 ± 7.9 72 ± 15 1.13 ± 0.23 63 ± 12 10.2 ± 1.6 ND 48 ± 10°° 6.3 ± 3.6°° 7.1 ± 3.5°° 67 ± 16° 1.04 ± 0.31° 68 ± 15 ° 10.9 ± 2.1° °0.05