Importance of smooth and sustained blood pressure control in preventing cardiovascular morbidity and mortality

Current management guidelines in hypertension define the magnitude or blood pressure lowering required from antihypertensive therapy to favourably alter cardiovascular prognosis, In addition, however, the manner in which blood pressure is reduced also influences outcome, and anti hypertensive therapy should induce smooth and sustained blood pressure control throughout the 24-h dosing interval. Ambulatory blood pressure recording techniques, in particular, have allowed the quantitative measurement of parameters such as the short-term variability of blood pressure, which correlates significantly with cardiovascular damage in patients with hypertension. The smoothness index has been developed as an index of the homogeneity of the blood pressure reduction obtained over the 24 hours by any given treatment during a long-term trial in patients with hypertension. This parameter is more predictive of a favourable effect of antihypertensive therapy (regression of left ventricular hypertrophy) during antihypertensive therapy than the widely used trough:peak ratio. The smoothness index is a useful new tool for comparing the quality of blood pressure lowering with different anti hypertensive agents. For example, candesartan cilexetil, a potent and long-acting AT(1)-receptor blocker, increased the smoothness index by a significantly greater extent than the prototype AT(1)-receptor blocker, losartan, implying a more smooth and sustained antihypertensive effect.