The irrelevance of the clinical arterial pressure with respect to outpatient pressure in defining the risk of left ventricular hypertrophy in essential arterial hypertension

To investigate whether the level of clinical blood pressure (BP) may serve to stratify the risk of left ventricular (LV) hypertrophy in essential hypertension regardless of the level of ambulatory BP, we performed 24-hour noninvasive ambulatory BP monitoring and echocardiography in 115 consecutive hypertensive patients who had never been treated before and in 92 normotensive subjects. Hypertensive patients were grouped according to the difference between the observed clinical BP and the predicted value of clinical BP, defined by regressing the observed clinical BP on the 24-hour average of the ambulatory BP: "low" clinical BP group (clinical systolic BP less than = 10 mmHg, diastolic BP less than = 6 mmHg than predicted values), "high" clinical BP group (systolic greater than = 10 mmHg, diastolic greater than = 6 mmHg than predicted values), "intermediate" clinical BP group (values within the above mentioned limits). Ambulatory BP did not show any statistically significant differences between the three groups. LV mass index was higher in hypertensive patients in each of the three groups (including the "low" clinical BP group) as compared with the normotensive group (all p less than 0.01), but did not show any statistically significant difference among the three groups of hypertensive patients, either defined by systolic BP or by diastolic BP. Other indexes of LV anatomy (relative wall thickness, cross-sectional area) showed a similar pattern.(ABSTRACT TRUNCATED AT 250 WORDS)