Plasma lipoprotein particle concentrations in postmenopausal women with unstable coronary artery disease. Analysis of diagnostic accuracy using receiver operating characteristics

Background, The contribution of plasma lipids to cardiovascular risk is usu ally evaluated by measuring plasma concentrations of total cholesterol, tri glycerides and HDL cholesterol, and calculating LDL cholesterol concentrati on, We investigated plasma concentrations of apolipoproteins and lipoprotei n particles in women with unstable coronary artery disease (CAD) to evaluat e whether these, better than the routine lipid status, could differentiate women with and without coronary atherosclerosis. Methods. Blood samples for lipid analyses were collected from 119 angiograp hically examined postmenopausal 49-79-year-old women with unstable CAD, and from 101 age-matched controls. Mean plasma concentrations were compared an d the discriminatory ability of the different variables were tested using r eceiver operating characteristics (ROC). Results. At coronary angiography 19% had normal vessels and 81% had coronar y atherosclerosis. A disturbed triglyceride metabolism was the most pronoun ced lipid abnormality in women with unstable CAD and coronary atheroscleros is. ROC showed that none of the evaluated variables had a particularly high discriminatory power regarding unstable CAD or coronary atherosclerosis. T he ratio cholesterol/HDL cholesterol was best with an ROC area of 0.79, Fur thermore, the newer lipid variables, i.e. lipoprotein particles and apolipo proteins, were no better than the traditional variables. Conclusion Lipoprotein changes reflecting a disturbed triglyceride metaboli sm are most pronounced in women with unstable CAD and coronary atherosclero sis. Lipoprotein particles and apolipoproteins alone were no better than li pids and lipoproteins in separating women with from those without coronary atherosclerosis. Our study does not support the measurement of apolipoprote ins and lipoprotein particles on the basis of diagnostic accuracy alone.