Predictive value of lipoprotein (a) and apolipoprotein A1 in patients with angiographycally evaluated coronary stenosis

To examine the relationship between blood levels of lipids, hemostatic and inflammatory markers and the presence of angiographycally evaluated coronary stenosis. We included 397 consecutive patients (267 males and 130 females) who were admitted to the hospital because of an acute episode of chest pain. Each patient underwent a coronariography using the Seldinger technique. A blood sample was drawn to analyze lipids -total cholesterol, high density lipoproteins-cholesterol (HDLc), triglycerides, low density lipoproteins-cholesterol (LDLc), apolipoprotein A1, apolipoprotein B100, lipoprotein (a)-, hemostatic (fibrinogen, D-dimmer), and inflammatory (C-reactive protein, leukocyte count) markers. To evaluate the differences between mean values of quantitative variables, the Student's t-test was used for parametric variables and the Mann Whitney U test for non-parametric variables. Categorical variables were compared using the chi-square test. A logistic regression analysis was employed to determine the influence of high levels of the studied parameters on the presence of coronary obstruction. 295 patients had coronary stenosis (group 1) and 102 had not a significant obstruction (group 2). Patients with coronary stenosis had higher values of lipoprotein (a), D-dimmer, C-reactive protein and leukocyte count and lower HDLc, apolipoprotein A1 and total cholesterol. When markers were dichotomized in high values (fourth quartile) and low (first-third quartile), high lipoprotein (a) (odds ratio [OR] = 2.508; 95% confidence interval [CI], 1.222-5.145) and apolipoprotein A1 levels (OR = 0.472; 95% CI, 0.267-0.837) were significant using the multivariate logistic regression model adjusted sex, tobacco and age. Among patients undergoing coronary angiography, high lipoprotein (a) levels are independently associated with the presence of coronary obstruction whereas high apolipoprotein A1 values show a protective effect.