Coronary vessel distensibility is reduced with atherosclerosis and normal aging, but direct measurements have historically required invasive measurements at cardiac catheterization. Therefore, we sought to assess coronary artery distensibility noninvasively using 3.0 Telsa coronary magnetic resonance imaging (MRI) and to test the hypothesis that this noninvasive technique can detect differences in coronary distensibility between healthy subjects and those with coronary artery disease (CAD). A total of 38 healthy, adult subjects (23 men, mean age 31 ± 10 years) and 21 patients with CAD, diagnosed using x-ray angiography (11 men, mean age 57 ± 6 years) were studied using a commercial whole-body MRI system. In each subject, the proximal segment of a coronary artery was imaged for the cross-sectional area measurements using cine spiral MRI. The distensibility (mm Hg-1 × 103) was determined as (end-systolic lumen area - end-diastolic lumen area)/(pulse pressure × end-diastolic lumen area). The pulse pressure was calculated as the difference between the systolic and diastolic brachial blood pressure. A total of 34 healthy subjects and 19 patients had adequate image quality for coronary area measurements. Coronary artery distensibility was significantly greater in the healthy subjects than in those with CAD (mean ± SD 2.4 ± 1.7 mm Hg-1 × 103 vs 1.1 ± 1.1 mm Hg-1 × 103, respectively, p = 0.007; median 2.2 vs 0.9 mm Hg-1 × 103). In a subgroup of 10 patients with CAD, we found a significant correlation between the coronary artery distensibility measurements assessed using MRI and x-ray coronary angiography (R = 0.65, p = 0.003). In a group of 10 healthy subjects, the repeated distensibility measurements demonstrated a significant correlation (R = 0.80, p = 0.006). In conclusion, 3.0-Tesla MRI, a reproducible noninvasive method to assess human coronary artery vessel wall distensibility, is able to detect significant differences in distensibility between healthy subjects and those with CAD.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine