Lipoprotein A, APO A phenotypes and dyslipidemia in acute coronary syndromes

ABSTRACT

Although several retrospective studies have shown a strong correlation between lipoproteins and atherosclerotic heart disease, the correlation is unclear in cases with coronary vasospasm. This study sought to examine dyslipidemia including lipoprotein[a] [Lp[a]] and Apo[a] phenotypes in coronary artery disease. One hundred and fifteen patients with mean age of 58.7 +/- 13 years suffering from coronary artery disease were selected. They were divided into groups with stable angina pectoris [SA], unstable angina [USA], acute myocardial infarction [AMI]. Control group consisted of 40 age and sex matched apparently healthy individuals. The lipids and lipoproteins including Lp[a] were measured using standard methods. Apo[a] phenotypes were evaluated by SDS-PAGE electrophoresis followed by immunoblotting. In patients with coronary artery disease, high-density lipoprotein cholesterol [HDL-C] levels were significantly lower than those in control [p<0.01], but in SA its level was higher than those of USA and AMI [p<0.05]. The levels of triglyceride and very low-density lipoprotein cholesterol [VLDL-C] were higher in SA and no significant differences were noticed in those of total cholesterol, but the concentrations of low-density lipoprotein cholesterol [LDL-C] in USA and AMI were significantly higher than those of SA and control groups. The ApoB concentration was markedly higher in USA group [p<0.002]. The mean +/- SD levels of total Lp[a] in USA and AMI groups were higher than those of SA and control groups [p<0.001]. Comparing the frequencies of low molecular weight [LMW] and high molecular weight [HMW] Apo[a] phenotypes of patients with control group, high frequencies of LMW Apo[a] and high levels of Lp[a] were noticed in USA and AMI groups [p<0.01 in both cases]. Low serum HDL-C and high serum LDL-C and Lp[a] levels were characteristic in patients with USA and AMI. Comparing the frequencies of Apo[a] phenotypes in SA, USA and AMI with those of control it was concluded that Apo[a] phenotyping along with serum levels of Lp[a], HDL-C and LDL-C could be a useful risk predictors for the development of acute coronary syndromes and may be used in discrimination of different types of the coronary artery diseases