Carotid Intima-Media Thickness and the Risk of First Stroke in Patients With Hypertension

Abstract

Background and Purpose - This study aimed to investigate the association between mean carotid intima-media thickness (cIMT) and the risk of first stroke and examine any possible effect modifiers in patients with hypertension. Methods - A total of 11 547 hypertensive participants without history of stroke from the CSPPT (China Stroke Primary Prevention Trial) were included in this analysis. The primary outcome was first stroke. Results - Over a median follow-up of 4.4 years, 726 first strokes were identified, of which 631 were ischemic, and 90 were hemorrhagic. A per SD increase in mean cIMT was positively associated with the risk of first stroke (hazard ratio [HR], 1.11 [95% CI, 1.03-1.20]), and first ischemic stroke (HR, 1.10 [95% CI, 1.01-1.20]). Moreover, when cIMT was categorized in quartiles, the higher risks of first stroke (HR, 1.31 [95% CI, 1.06-1.61]) and first hemorrhagic stroke (HR, 2.25 [95% CI, 1.11-4.58]) were found in participants in quartile 2 to 4 (≥0.66 mm), compared with those in quartile 1 (<0.66 mm). More importantly, the cIMT-first stroke association was significantly stronger in participants with higher mean arterial pressure (≥109.3 [quintile 5] versus <109.3 mm Hg, P-interaction=0.024) or diastolic blood pressure levels (≥90.7 [quintile 5] versus <90.7 mm Hg, P-interaction=0.009). Conclusions - There was a significant positive association between baseline cIMT and the risk of first stroke in patients with hypertension. This association was even stronger among those with higher mean arterial pressure or diastolic blood pressure levels.