Apolipoprotein A-I as a Marker of Angiographically Assessed Coronary-Artery Disease

This study was designed to determine whether the plasma level of apolipoprotein A-I is a better discriminator of angiographically documented coronary-artery disease than the level of high-density–lipoprotein (HDL) cholesterol in male subjects. The level of plasma apolipoprotein A-I in 83 patients with coronary-artery disease was 96.7±4.2 mg per deciliter (mean ±S.E.M.), which was significantly lower (P<0.0001) than the level in 25 patients without coronary-artery disease (146.9±2.1 mg per deciliter). The levels of HDL cholesterol were also lower (P<0.0001) in patients with coronary-artery disease (31.9±1.5 mg per deciliter) than in those without it (45.9±2.3 mg per deciliter). A stepwise discriminant analysis, however, indicated the superiority of apolipoprotein A-I over HDL cholesterol in detecting coronary-artery disease. Furthermore, a linear discriminant analysis suggested that although HDL cholesterol by itself was a discriminator of coronary-artery disease, it did not provide a substantial increase in discriminatory value over that provided by apolipoprotein A-I; in contrast, apolipoprotein A-I levels added discriminatory value to the information obtained by measuring HDL cholesterol alone. We conclude that apolipoprotein A-I by itself is more useful than HDL cholesterol for identifying patients with coronary-artery disease. (N Engl J Med 1983; 309:385–9).