The first manifestation of coronary artery disease (CAD) may be sudden death. The main focus for primary prevention is to identify individuals at risk for cardiovascular events. Cardiovascular events occur from preexisting CAD, providing an opportunity for risk intervention. Carotid ultrasound (CU) and lipoprotein-a [Lp(a)] have been proposed as valuable tools for early detection of CAD, but have not been tested together in the same group of young adults at low risk per clinical guidelines.
To evaluate the accuracy of Lp(a) and CU in predicting CAD.
213 young adults (men ≤ 55; women ≤ 65), without previous CAD or anti-lipemic therapy were evaluated with coronary angiography (CA) and CU. Blood samples were drawn for lipid analysis and Lp(a). CAD was defined as stenosis severity ≥ 50%. CU was defined as abnormal for maximal intima media thickness (IMT) > 1.0 mm in the main body; plaques or calcium at the main body, bulb, or proximal branches.
Mean age 50.6 ± 7.5. Lipid profiles were normal (total cholesterol 195.8 ± 36.3, LDL 122.9 ± 30.1, HDL 51.0 ± 14, triglycerides 145.9 ± 76.2). 93% were classified as low risk per NCEP III guidelines. 63 had severe CAD and had higher Lp(a) levels (30 vs 14, p = 0.004). Lp(a) had low sensitivity (33%) but high specificity (87%) for angiographic CAD (OR 3.4; CI: 1.7 – 7.01). The sensitivity for CU was 75%; specificity 50%; and negative predictive value 83% (OR 2.5; CI: 1.3 – 4.8). Multivariate analysis revealed that Lp(a) and abnormal CU were independently predictive of angiographic CAD.
Lp(a) and CU are predictive of CAD in young adults classified as low risk per NCEP III guidelines. However, CU is more sensitive, and its accessibility may make it more preferable for screening in primary prevention.
The ability of CU to predict CAD provides an opportunity to improve risk stratification in young adults whose CHD risk is underestimated by clinical guidelines
K.O. Akosah, None.