Prognosis of acute ST-elevation myocardial infarction depending on the morphological features of intracoronary thrombi

Risk stratification among patients with acute ST-segment elevation myocardial infarction (STEMI) is very important. Morphological features of intracoronary thrombus significantly influence the prognosis. Aim. To estimate the prognosis after STEMI treated with primary percutaneous coronary intervention (PCI) depending on the morphological structure of intracoronary thrombi obtained during manual thromboaspiration. Materials and methods. Totally 97 patients with STEMI who underwent primary PCI were included into the study. Morphological structure of intracoronary thrombi obtained by manual thromboaspiration was evaluated in all participants. Further, the different structure of thrombi influence on the risk of developing a composite endpoint was determined, which represented a death, myocardial infarction, revascularization, and angina symptoms onset or worsening. The duration of follow-up was 24 months. Results. In 24 months after primary PCI, the occurrence of the endpoint correlated significantly only with macroscopic signs of intracoronary clots, negatively with white (r = -0.21, P = 0.05) and red thrombi (r = -0.30, P < 0.01), and positively with mixed thrombi (r = 0.41, P < 0.001). Using the logistic regression, the factors were revealed which in a case of combined action, may increase the risk of the combined endpoint: old blood clots (V1), the presence of microchannels (V2), peripheral leukocyte infiltration (V3), and gross mixed thrombi (V4). The following model was developed for calculating the probability of these factors influence on the occurrence of cardiovascular events included into the endpoint: Z=2.37 xV1 + 2.21 xV2 + 1.69 xV3 + 3.24 xV4-5.60. The model is reliable (P < 0.0001) with a sensitivity of 83.33 % and a specificity of 88.24 %. Conclusions. Despite the similar clinical manifestations and duration of the disease, intracoronary thrombi that cause STEMI differ significantly. Their morphological characteristics were related to the prognosis. These characteristics may be used for construction of a reliable risk scale that is suitable for clinical practice.