Demonstration of the Glagov phenomenon in vivo by CT coronary angiography in subjects with elevated Framingham risk

Computed tomography coronary angiography (CTA) is a novel, non-invasive method for coronary plaque detection and quantification. We hypothesized that CTA can detect early vessel wall thickening with preserved luminal size in patients without known coronary artery disease and intermediate/ high Framingham Risk Score (FRS) compared to those with low FRS. Vessel-wall and plaque geometrical and compositional parameters were measured on CTA in 375 coronary segments with a highly standardized method. These parameters were then compared in patients with low versus intermediate/ high FRS. The relationship between coronary artery calcium by non-contrast CT scanning (Agatston score) and percent atheroma volume (PAV) was determined by linear regression. P value<0.05 was considered significant. PAV and remodeling index were significantly higher in patients with intermediate/high FRS compared to those with low FRS (45.9 ± 6.8 vs. 42.3 ± 6.7; P = 0.004) and (0.97 ± 0.15 vs. 0.92 ± 0.13; P = 0.04), while minimal luminal diameter and minimal luminal area were similar. There was significant correlation between Agatston score and PAV (r² = 0.42, P = 0.0036). However, Agatston score and plaque compositional parameters were similar between the groups. In conclusion, we demonstrated that CTA can detect early vessel-wall thickening with preserved luminal size in patients with intermediate/ high versus low FRS.