Baseline Values but Not Treatment-Induced Changes in Carotid Intima-Media Thickness Predict Incident Cardiovascular Events in Treated Hypertensive Patients

Abstract

Baseline carotid intima-media thickness (IMT) and plaques are considered predictors of cardiovascular events, but whether they maintain predictive value in treated hypertensive patients and whether time-related (or treatment-induced) IMT changes are additional predictors are unknown. Analyses were performed of the data from the European Lacidipine Study on Atherosclerosis (ELSA), a large, randomized, intervention trial in which 2334 hypertensive patients from 7 European countries were followed up under effective antihypertensive treatment for 3.75 years. Kaplan-Meier curves indicated progressively lower survival free of any type of outcome except stroke, with increasing baseline IMT quartiles or increasing IMT values, even after adjustment for major baseline risk factors. Incidence of any outcome except stroke also was related to baseline number of carotid plaques. However, when both baseline and on-treatment IMT values were entered in Cox proportional-hazards models, differences in IMT compared with baseline did not predict cardiovascular outcomes. Although on-treatment rather than baseline IMT values significantly entered some of the proportional-hazards models, baseline and on-treatment IMTs were highly correlated, and therefore these results are inconclusive. ELSA shows that carotid intima-media thickening and plaques are important added risks of cardiovascular outcomes in a treated hypertensive population independently of blood pressure and traditional risk factors. However, the analysis failed to show a predictive role of treatment-dependent IMT changes. These negative conclusions should be tempered by the limitations inherent in the smallness of these changes compared with the large individual differences in baseline IMTs.