Large artery wall thickening and its determinants under antihypertensive treatment: the IMT-INSIGHT study

Abstract

Background: Calcium antagonists retard progression of intima-media thickness (IMT), but whether this retardation covers heterogeneous individual patient responses of IMT change is unknown.

Methods: Hypertensive patients treated for 4 years with nifedipine (n = 115) or coamilozide (n = 127) underwent ultrasound measurements of carotid IMT at baseline, 4 months later, and then every year.

Results: A histogram of individual slopes of IMT change (least square regression of IMT to time) during treatment identified three categories of slopes according to the 20th and 80th percentiles of distribution: lower, intermediate and higher percentiles of IMT slope; the proportion of categories of IMT slope differed between treatments (P < 0.05), due to a more frequent lower slope percentile under nifedipine (27%) than under coamilozide (14%); within-group differences between IMT slope categories were: (i) increased baseline IMT associated with lower IMT slope percentile in nifedipine group (P < 0.001) and (ii) more frequent carotid plaque associated with higher IMT slope percentile in both treatment groups (P < 0.05). Analysis of overall patients showed that IMT slope was associated negatively with nifedipine treatment (P < 0.01) and baseline IMT (P < 0.001) and positively with carotid plaque (P < 0.01); the relationship between IMT slope and baseline IMT was negative under nifedipine and flat under coamilozide, and the presence of plaque reset both relationships towards a higher IMT slope; the between-treatment difference in IMT slope was different between tertiles of baseline IMT (P = 0.016).

Conclusions: The differences in IMT slope between nifedipine and coamilozide increase with increasing baseline IMT.