Long-term influence of antihypertensive treatment on arterial stiffness assessed by ambulatory measurement of the QKD interval.

An increase in arterial stiffness is an important risk factor for cardiovascular events. However, there are few data on the long-term evolution of arterial stiffness in treated hypertensives. We evaluated the progression of arterial stiffness in 120 initially untreated hypertensive patients whose arterial stiffness was assessed by the ambulatory monitoring of the QKD interval measured at baseline and then more than 1 year later. The ambulatory method produced an isobaric index of arterial stiffness, the QKD(100-60). Out of these patients, 30 with white coat hypertension did not receive any treatment, and over a mean follow-up period of 5 years their QKD(100-60) was unchanged. The 90 other patients received antihypertensive treatment (average of 2.5 classes of drug) over a mean period of 6 years. In this population, the mean 24 h blood pressure (BP) was significantly reduced (-9 mm Hg for systolic BP, -6 mm Hg for diastolic BP) and the QKD(100-60) was prolonged (+3.5 ms, P<0.05). The presence of type 2 diabetes in 17 of these patients was the sole factor negatively correlated with the improvement in QKD(100-60). An initial reduction in QKD(100-60) appeared to be a factor of resistance to the BP-lowering action of the medication. Antihypertensive treatment has a long-term action on arterial stiffness. The existence of diabetes appeared to have a negative influence on this improvement. Furthermore, an increase in arterial stiffness may be a factor of resistance to the action of antihypertensive medication.