Aim: To determine the incidence of recent coronary thrombus in a population died of acute myocardial infarction (AMI) and to evaluate the relation between its presence and some clinical parameters (age, gender, time interval between the onset of symptoms and death and cause of death).
Population and methods: 167 hearts of consecutive patients died of AMI and without thrombolytic therapy. Hearts were fixed in formaldehyde 10% for two weeks and then the epicardial coronary arteries were divided in 5 mm segments, which were examined by visual inspection to identify recent thrombi. Cuts for microscopical observation were obtained in cause of doubt. In each patients a clinical protocol with 64 parameters is performed. In statistical treatment Pearson's dispersion test and Student's t test were used.
Results: We found coronary thrombus in the infarction related artery in 74%. The thrombus distribution in the epicardiac coronary arteries was the following: 47% in the anterior descendent artery, 27% in the right coronary artery, 21% in the left circumflex and 5% in the left main. The comparison between the groups with and without coronary thrombus showed no differences in age and gender, but the time interval between AMI and death was shorter in the group with thrombus. Concerning the different causes of death (cardiac failure, cardiac rupture and others) the coronary thrombus prevailed in the group with left ventricule free wall rupture. There was no influence of the time interval between AMI and death on the larger prevalence of coronary thrombus found in cardiac rupture.
Conclusions: The frequency of recent coronary thrombus in the infarction related artery was of 74% in this group of patients died of AMI without thrombolytic therapy. The presence of coronary thrombus was not related with patients age or gender. The frequency of coronary thrombus was inversely proportional to the time interval between AMI and death, and larger in the group with left ventricule free wall rupture.