Association of plasma lipoproteins with angiographically defined coronary artery disease

Lipoprotein (a) and other lipoprotein variables have been correlated with angiographic severity of coronary artery disease. However, pattern of lipoprotein (a) distribution in various racial groups has been found to be different. To study this relationship in the Indian patients, plasma levels of lipoprotein (a) and other lipoprotein variables were examined in 144 consecutive patients undergoing coronary angiography. Total cholesterol and cholesterol content of various lipoproteins were assayed by chemical methods, and in 116 patients lipoprotein (a) was detected by gel electrophoresis. Lipoprotein (a) was positive in a total of 78 (67%) patients, and its positivity in the four angiographic groups with normal coronaries, single vessel, double vessel, and triple vessel disease was 69, 78, 61 and 67 percent respectively. Interestingly, lipoprotein (a) greater than 75 percentile tended to be more frequent in patients with increasing severity of coronary artery disease: 15%, 21%, 25% and 28% in the four groups, respectively. However, this was not statistically significant. Plasma levels of total cholesterol, cholesterol content of other lipoproteins and triglycerides were not significantly different in these four groups of patients. This study, therefore, shows that there is no significant correlation of lipoprotein (a) positivity with angiographic severity of coronary artery disease in our group of Indian patients, although higher values are more frequently present in patients with severe disease.