Cholesteryl Esters Associated With Acyl-CoA:cholesterol Acyltransferase Predict Coronary Artery Disease in Patients With Symptoms of Acute Coronary Syndrome
Academic Emergency Medicine, 06/12/2012
Miller CD et al. – Plasma levels of acyl–CoA:cholesterol acyltransferase (ACAT2)–cholesteryl ester (CE) have strong potential to predict a patient’s likelihood of having coronary artery disease (CAD) when considered in a clinical model but not when used alone. In turn, a clinical model containing ACAT2–CE could reduce the need for cardiac imaging after the exclusion of myocardial infarction (MI).Methods
- A single–center prospective cohort design enrolled participants with symptoms of acute coronary syndrome (ACS) undergoing coronary computed tomography angiography (CCTA) or invasive angiography.
- Plasma samples were analyzed for CE composition with mass spectrometry.
- The primary endpoint was any CAD determined at angiography.
- Multivariable logistic regression analyses were used to estimate the relationship between the sum of the plasma concentrations from cholesteryl palmitoleate (16:1) and cholesteryl oleate (18:1) (defined as ACAT2–CE) and the presence of CAD.
- The added value of ACAT2–CE to the model was analyzed comparing the C–statistics and integrated discrimination improvement (IDI).
- The study cohort was composed of 113 participants with a mean (±standard deviation [SD]) age of 49 (±11.7)years, 59% had CAD at angiography, and 23% had an MI within 30days.
- The median (interquartile range [IQR]) plasma concentration of ACAT2–CE was 938µmol/L (IQR=758 to 1,099µmol/L) in patients with CAD and 824µmol/L (IQR=683 to 998µmol/L) in patients without CAD (p=0.03).
- When considered with age, sex, and the number of conventional CAD risk factors, ACAT2–CE levels were associated with a 6.5% increased odds of having CAD per 10µmol/L increase in concentration.
- The addition of ACAT2–CE significantly improved the C–statistic (0.89 vs. 0.95, p=0.0035) and IDI (0.15, p<0.001) compared to the reduced model.
- In the subgroup of low–risk observation unit patients, the CE model had superior discrimination compared to the Diamond–Forrester classification (IDI=0.403, p<0.001).