SERUM LIPOPROTEIN(A) LEVEL IS RELATED TO THROMBIN GENERATION AND SPONTANEOUS INTERMITTENT CORONARY-OCCLUSION IN PATIENTS WITH ACUTE MYOCARDIAL-INFARCTION

Background Thrombotic occlusion of the infarct-related coronary artery is often intermittent in the early, evolving phase of acute myocardia l infarction. To assess their relationship to this pattern of coronary occlusion, serum or plasma concentrations of cholesterol, triglycerid e, lipoprotein(a), and coagulation and fibrinolytic factors were measu red in venous blood before the initiation of thrombolytic therapy. Met hods and Results Thirty-two patients (23 men, 9 women; age, 30 to 70 y ears) with acute myocardial infarction received intravenous recombinan t tissue plasminogen activator (20 to 60 megaunits) within 6 hours of the onset of symptoms. Continuous ECG ST-segment recording demonstrate d intermittent occlusion of the infarct-related coronary artery in 12 patients (group 1) before the start of thrombolytic treatment and pers istent occlusion in 20 patients group 2). Groups 1 and 2 were similar in age, sex, race, duration of symptoms, blood sample collection time, location of the infarct-related coronary artery, and extent of corona ry artery disease. The serum level (median [interquartile range]) of l ipoprotein(a) was 34 (13 to 47) mg/dL versus 11.5 (5 to 27) mg/dL. (P= .02), and the plasma level (median [interquartile range]) of thrombin- antithrombin III complex was 10.85 (6.4 to 21.5) versus 6.8 (4.2 to 8. 7) mu g/L(-1) (P<.04) in groups 1 and 2, respectively. The levels of t he other factors were similar in both groups. Conclusions The phenomen on of spontaneous intermittent closure and reopening of coronary arter ies early during acute myocardial infarction in humans is associated w ith a higher Level of lipoprotein(a) and of a marker of thrombin gener ation, suggesting that lipoprotein(a) and thrombin are closely related to coronary patency in these patients.