Course of serum lipoprotein(a) and acute phase protein levels in patients undergoing open heart surgery

BACKGROUND: Lipoprotein(a) [Lp(a)] is an important risk factor in the pathogenesis of coronary artery disease because of its thrombogenic and atherogenic properties. Lp(a) also displays another property by acting as an acute phase reactant. METHODS: In this work, the study group consisted of 20 male patients having coronary artery bypass under cardiopulmonary bypass (CPB). Preoperative and postoperative levels of plasma total cholesterol, triglyceride, apolipoprotein A1 (Apo A1), apolipoprotein B (Apo B), alpha-1 antitrypsin (a1-AT), alpha-2 macroglobulin (alpha 2-MG), alpha-1 acid glycoprotein (alpha 1-AG), Lp(a) were measured in all patients one day before and after the 1st, 2nd, 4th, and 10th days of CPB. RESULTS: It was observed that the levels of Lp(a) levels gradually reached the preoperative levels at the 10th postoperative day period. Observed change of the Lp(a) levels was similar to that of the other acute phase proteins which are synthesized and released from liver. In contrast, alpha 2-MG has shown different behaviour in terms of operative values. The changes observed for all these 3 parameters were found to be statistically significant (p<0.01). CONCLUSIONS: The data has indicated that Lp(a) levels show similar progress with alpha 2-MG levels. It can be concluded that serum levels of Lp(a) after coronary arterial bypass decrease depending upon several factors and reach basal levels at the end of a 10 day-period of postoperation. The main cause for this decrease might result from the contact of blood with foreign surfaces of the heart-lung machine.