From 'optimal' to 'borderline' blood pressure in subjects under chronic antihypertensive therapy

The ESH2003 report (J Hypertens 2003, 21:1011-1053) has classified brachial blood pressure into six groups reflecting the consistently increasing cardiovascular risk caused by high blood pressure. Chronically treated hypertensive individuals with well-controlled blood pressure retain higher cardiovascular risk than normotensive untreated individuals. Differences between these groups in arterial stiffness, pressure wave reflections and central blood pressure, which are all predictors of cardiovascular risk independently of peripheral blood pressure, have never been studied.

A cohort of 216 treated subjects with controlled hypertension was compared with 105 never-treated normotensive controls, according to the ESH2003 blood pressure groups. Aortic stiffness (pulse wave velocity; PWV), carotid wave reflections (augmentation index; AI) and carotid pressures were measured non-invasively, by pulse wave analysis. Systolic blood pressure (SBP) and pulse pressure (PP) amplification between brachial and carotid arteries were estimated.

The distribution of subjects in each subgroup of the untreated and treated populations was: 'optimal', 21 versus 43; 'normal', 44 versus 77; 'borderline', 40 versus 96. Brachial blood pressure, carotid SBP and PP did not differ between the two populations, but a constant interaction between blood pressure classification and treatment effect on PWV, AI and blood pressure amplification was found. Compared with untreated subjects, treated subjects had higher AI and lower blood pressure amplification (in the optimal group) and higher PWV (in the borderline group).

'Optimal' to 'borderline' blood pressure control in chronically treated hypertensive individuals is associated with impaired properties of the large and small arteries. These results suggest that antihypertensive treatment strategies with more beneficial effects on arterial properties are needed.