Evidence of Carotid Atherosclerosis Vulnerability Regression in Real Life From Magnetic Resonance Imaging: Results of the MAGNETIC Prospective Study

Abstract

Background Atherosclerosis vulnerability regression has been evidenced mostly in randomized clinical trials with intensive lipid-lowering therapy. We aimed to demonstrate vulnerability regression in real life, with a comprehensive quantitative method, in patients with asymptomatic mild to moderate carotid atherosclerosis on a secondary prevention program. Methods and Results We conducted a single-center prospective observational study (MAGNETIC [Magnetic Resonance Imaging as a Gold Standard for Noninvasive Evaluation of Atherosclerotic Involvement of Carotid Arteries]): 260 patients enrolled at a cardiac rehabilitation center were followed for 3 years with serial magnetic resonance imaging. Per section cutoffs (95th/5th percentiles) were derived from a sample of 20 consecutive magnetic resonance imaging scans: (1) lipid-rich necrotic core: 26% of vessel wall area; (2) intraplaque hemorrhage: 12% of vessel wall area; and (3) fibrous cap: (a) minimum thickness: 0.06 mm, (b) mean thickness: 0.4 mm, (c) projection length: 11 mm. Patients with baseline magnetic resonance imaging of adequate quality (n=247) were classified as high (n=63, 26%), intermediate (n=65, 26%), or low risk (n=119, 48%), if vulnerability criteria were fulfilled in ≥2 contiguous sections, in 1 or multiple noncontiguous sections, or in any section, respectively. Among high-risk patients, a conversion to any lower-risk status was found in 11 (17%; P=0.614) at 6 months, in 16 (25%; P=0.197) at 1 year, and in 19 (30%; P=0.009) at 3 years. Among patients showing any degree of carotid plaque vulnerability, 21 (16%; P=0.014) were diagnosed at low risk at 3 years. Conclusions This study demonstrates with a quantitative approach that vulnerability regression is common in real life. A secondary prevention program can promote vulnerability regression in asymptomatic patients in the mid to long term.

Keywords: cardiac rehabilitation; carotid atherosclerosis; magnetic resonance imaging; modifiable risk factors; secondary prevention; vulnerability regression.

Figure 1. Regression of carotid plaque vulnerability during the study in patients who at baseline were at high risk (A), and at intermediate or high risk (B).

*Vulnerability risk of atherosclerosis defined by the quantitative assessment of the lipid‐rich necrotic core, the fibrous cap, and intraplaque hemorrhage. HR indicates high risk; IR, intermediate risk; and LR, low risk.

Figure 2. Examples of highly vulnerable plaques at baseline with favorable evolution at end of study.

Figure 3. Kaplan–Meier survival curves (all‐cause death) of patients with vulnerable carotid plaques (high or intermediate risk) and patients with stable atherosclerosis at baseline.