Vessel Wall Volume and Plaque Volume Should Replace Carotid Intima–Media Thickness

In this issue of the journal, Abe et al.1 report that carotid intima–media thickness (IMT) predicted stroke risk among black hypertensive adults in the Jackson Heart Study. They commendably avoided the common error of referring to IMT as “subclinical atherosclerosis,” and correctly interpreted their findings in light of the higher prevalence of stroke due to hypertensive small vessel disease in African-Americans. In this relatively young population (57 ± 10 years at baseline), each standard deviation increase in IMT was associated with ~30% higher risk of stroke (hazard ratio 1.27, 95% confidence interval: 1.08–1.49). This was evident even in participants with well-controlled blood pressure, with a 56% increase in the odds of stroke for each 0.17 mm increase in IMT. Net reclassification of stroke risk was improved by the addition of IMT to the pool cohort equations, with reclassification of 58% of participants with stroke from low/borderline- to a higher-risk category, and reclassification of 28% without stroke to a lower-risk category. This gave a significant improvement of net reclassification of 0.22 (0.10–0.30). As would be expected, IMT did not predict coronary events in this population, but it was a stronger predictor of stroke than was a coronary calcium score.2