Statin Use Is Associated With Fewer High-Risk Plaques
Coronary computed tomography angiography (CCTA) studies suggest that the presence of high-risk plaque (HRP) features (i.e., positive remodeling and low CT plaque attenuation) is independently associated with a 10- to 20-fold increased risk for a future acute coronary syndrome (ACS). Does statin therapy lower the prevalence of HRP as compared to those not on statins?
An observational cross-sectional subanalysis of the ROMICAT (Rule Out Myocardial Ischemia/Infarction Using Computer Assisted Tomography) II trial was utilized. Patients with suspected ACS in the emergency department (ED) who were enrolled in ROMICAT II randomized to CCTA and who had diagnostic image quality were included. Data on cardiovascular risk factors and whether on statin therapy at study entry were collected. The CCTA data sets were assessed for the presence of obstructive coronary artery disease (CAD) (>50% stenosis), noncalcified and calcified coronary atherosclerotic plaque, and HRP.
Of the 222 eligible patients (mean age 56.0 ± 7.9 years, 35% female), 34% (n = 75) were on a statin on admission, 84% (n = 186) had nonobstructive, 16% (n = 36) had obstructive CAD, and 25% (n = 56) had HRP. Patients on statins were older (mean age 58 vs. 54.7 years; p = 0.001) and had a higher mean number of risk factors (1.9 vs. 1.4, p = 0.001), yet were less likely to have any HRP (13.3% vs. 31.3%; p = 0.003), despite similar numbers of obstructive and nonobstructive CAD. Patients on statins with obstructive and nonobstructive CAD were 3-4 times less likely to have HRP as compared to patients not on statins. Patients on statins had a significantly higher coronary calcium score, a finding which was attenuated and insignificant after multivariate analysis adjustment for age, gender, number of risk factors, total plaque volume, and obstructive CAD.
Statin therapy alters the natural history of composition and morphology of coronary atherosclerosis by CT and intravascular ultrasound, which may be one mechanism by which statins lead to a reduction in cardiovascular events, in the setting of CCTA in patients with acute chest pain.
ROMICAT II was a multicenter, randomized, controlled trial that demonstrated CCTA incorporated early into an emergency department (ED) evaluation strategy improves clinical decision making for triage compared to a standard ED evaluation for patients with possible ACS. This study adds to the data suggesting that statins reduce the number of ‘vulnerable plaques,’ but falls short of firming the observation that by inducing healing, statins enhance coronary plaque calcification.
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