Serum lipoprotein [a] and risk of coronary heart disease: its relation to degree of coronary artery occlusion

To study the relationship between the serum lipoprotein [a] levels and the degree of coronary artery occlusion, 40 patients [32 males and 8 females] with a previous attack of acute myocardial infarction were included in this study. The age of pateints was ranged from 36 to 60 years [mean age = 47.13 +/- 5.5 years]. Patients were evaluated clinically and by laboratory means and underwent coronary angiography. They were classified into 3 groups according to coronary atherosclerosis score [CAS]; Group I comprised 20 patients with CAS /= 8. Results showed that the plasma levels of total cholesterol, triglycerides, LDL and HDL were not significantly differed among the different groups of the patients, while the plasma Lp[a] level was significantly increased from 20.27 +/- 7.25 mg/dl in group I to 32.00 +/- 8.70 mg/dl in group Il and to 52.71 +/- 14.5 mg/dl in group Ill, p <0.001. Correlation between the degree of coronary artery narrowing [as measured by CAS] and the plasma lipids revealed significant positive correlation only with Lp[a], r = 0.77, p <0.001. Regression model consists of Lp[a], cholesterol, triglycerides, LDLand HDL showed that Lp[a] is the most important risk factor associated with coronary artery occlusion, r[2] = 0.60, p <0.001. Thus Lp [a] is a major plasma lipid risk factor [or coronary heart disease and its level can predict the extent of the coronary artery narrowing