BACKGROUND A strong correlation between high serum Lp(a) levels, a genetic modification of cholesterol-low density lipoproteins (c-LDL), and increased coronary heart disease rate has been found. Transient increased serum levels of this lipoprotein during acute myocardial infarction (AMI) and surgical interventions have been found. METHODS METHODS we assessed complete lipidic pattern in a study series composed of 19 patients with AMI. We also evaluated the changes of Lp(a) serum levels within the first week of the disease in order to assess whether a correlation between this parameter and extent of necrotic myocardial area is present. METHODS study series was made up of 19 patients (13 males, 6 females; mean age 57.94+/-10.7 years) with AMI compared to 25 control subjects (12 males and 13 females; mean age 51.12+/-15.34 years). METHODS we also withdrew a blood sample on days 1, 3 and 7 from the onset of the AMI. On the first day we evaluated the serum levels of the following parameters: glycaemia, azotemia, creatininemia, urycaemia, total cholesterol, high density lipoprotein cholesterol (c-HDL), low density lipoprotein cholesterol (c-LDL), triglycerides, fibrinogen, creatinphosphokinase, aspartate aminotranspherase, thromboplastine time and prothrombinic activity. Lp(a) has been evaluated on day 1, 3 and 7 and after 6 months from AMI. We performed an ultrasound scanning (US) of the heart in day 7 for evaluation of the extent of necrotic myocardial area by observation of "segmental kinetic area". RESULTS Mean basal Lp(a) serum level was 28.94+/-29.78 mg/dl (as median 17), (normal values 0 to 25 mg/dl). This value was not changed on day 3 (mean 29.47+/-30.46 mg/dl, median 18), while significantly increased on day 7 (39.84+/-42.77, median 26, p=0.05). Spearman's rank correlation test showed a strong correlation between the increase of Lp(a) serum levels on day 7 and extent of necrotic myocardial area (r=0.696, p=0.001). CONCLUSIONS The positive correlation between mean Lp(a) values on day 1 and 7, and the size of the necrotic area, suggest that Lp(a) has an atherogenic and prothrombotic role. Moreover, elevated Lp(a) values were related to greater tissue damage. We believe that periodical determination of Lp(a) values in subjects with coronary disease is useful in order to predict further acute vascular events.