Early changes in arterial structure and function following statin initiation: quantification by magnetic resonance imaging

Abstract

Effective LDL-cholesterol (LDL-C) reduction improves vascular function and can bring about regression of atherosclerosis. Alterations in endothelial function can occur rapidly, but changes in atherosclerosis are generally considered to occur more slowly. Vascular magnetic resonance imaging (MRI) is a powerful technique for accurate non-invasive assessment of central and peripheral arteries at multiple anatomical sites. We report the changes in atherosclerosis burden and arterial function in response to open label statin treatment, in 24 statin-naïve newly diagnosed stable coronary artery disease patients. Patients underwent MRI before, and 3 and 12 months after commencing treatment. Mean LDL-C fell by 37% to 70.8 mg/dL (P<0.01). The plaque index (normalised vessel wall area) showed reductions in the aorta (2.3%, P<0.05) and carotid (3.1%, P<0.05) arteries at 3 months. Early reductions in atherosclerosis of aorta and carotid observed at 3 months were significantly correlated with later change at 12 months (R(2)=0.50, P<0.001; R(2)=0.22, P<0.05, respectively). Improvements in aortic distensibility and brachial endothelial function that were apparent after 3 months treatment were sustained at the 12-month time point.

Fig. 1

(a) Plaque index in the aorta is reduced in response to statin treatment. Significant reductions were observed between baseline and 3 months and between 3 and 12 months (* indicates P < 0.05 vs. baseline, † indicates P < 0.05 vs. 3 months). (b) Proton density weighted image of descending thoracic aorta showing a well-defined, eccentric, mildly lobulated plaque in the descending thoracic aorta (arrow). (c) Change in plaque index (ΔPI) at 3 months was significantly correlated to the change measured at 12 months.

Fig. 2

(a) Plaque index in the carotid arteries was reduced in response to statin treatment. Significant reductions were observed between baseline and 3 months but not between 3 and 12 months (* indicates P < 0.05 vs. baseline). (b) T2 weighted magnetic resonance image of the common carotid arteries (arrows) demonstrating bilateral non-obstructive common carotid plaques. (c) Change in plaque index (ΔPI) at 3 months was significantly correlated to the change measured at 12 months.