Visit-to-Visit Blood Pressure Variability, Carotid Atherosclerosis, and Cardiovascular Events in the European Lacidipine Study on Atherosclerosis

Background— In high-cardiovascular-risk treated hypertensive patients, the incidence of cardiovascular events has been reported to relate to visit-to-visit blood pressure (BP) variability. We investigated whether visit-to-visit BP variability is prognostically important in treated mildly to moderately hypertensive patients in whom treatment aims at avoiding events but also at preventing or delaying progression of organ damage. Methods and Results— We analyzed the pooled data from the European Lacidipine Study on Atherosclerosis (ELSA), a randomized, double-blind 4-year trial of the effect of lacidipine or atenolol on echographic carotid intima-media thickness. Visit-to-visit BP variability was assessed by the coefficient of variation or the SD of the mean on-treatment systolic BP (SBP) obtained at 6- (clinic BP) and 12- (24 hours BP) month intervals, respectively (1521 and 1264 patients, respectively). In a multivariable linear regression model, mean on-treatment clinic or 24-hour SBP, but not SBP coefficient of variation or SD, was associated with end-of-treatment carotid intima-media thickness. Intima-media thickness increased progressively from the lowest to highest quartile of mean on-treatment clinic or 24-hour SBP (adjusted P for trend=0.046 and 0.048) but not along similar quartiles of SBP coefficient of variation or SD. In a multivariable logistic regression model, mean BP, but not variability, was associated with cardiovascular outcomes. Conclusions— In mildly to moderately hypertensive patients, carotid intima-media thickness and cardiovascular outcomes were related to the mean clinic or ambulatory SBP achieved by treatment but not to on-treatment visit-to-visit clinic or 24-hour BP variability. Thus, when BP is modestly elevated, inconsistency of BP control between visits plays a less important prognostic role than long-term average BP levels.