P3586Influence of morphological features of intracoronary thrombi on ST segment resolution in patients with STEMI after primary PCI

Abstract

Abstract Background Coronary artery thrombosis is a key element in the onset of STEMI and its further course. Coronary clots significantly vary in their morphological features and types. Perhaps, it may be caused by individual differences in thrombus formation that could have a strong influence on STEMI course and prognosis. Purpose To elucidate the influence of morphological features of intracoronary thrombi (IT) on ST-segment resolution (the outcome) after primary PCI in patients with STEMI. Methods The study included 100 patients with STEMI (female 22%, male 78%) aged 57.81±10.26 years, who underwent PCI with manual thromboaspiration within the first 12 hours (mean 7.22±3.74 h) after the onset of symptoms. The obtained ITs were examined morphologically after hematoxylin & eosin staining by the standard method and by the method proposed by prof. Zerbino that allows determining the antiquity of fibrin according to its color. Each IT was classified by five morphological features: 1) “old” or “fresh” (according to Zerbino's staining); 2) with or without layered structure; and presence or absence of 3) microchannels, 4) peripheral infiltration with neutrophil leukocytes, 5) elements of atherosclerotic plaque. Correlations between these features and incidence of ST-segment resolution in 60 minutes after primary PCI for more than 50% from baseline were analyzed. Results Neither IT antiquity nor presence of the atherosclerotic plaque elements had any significant correlations with ST-segment resolution. Significant positive correlation was revealed with peripheral neutrophil infiltration (r=0.42, p<0.05), and negative correlations were found with layered arrangement IT (r=−0.31, p<0.05) and presence of microchannels (r=−0.56, p<0.05). Statistically significant mathematical prognostic model of ST-segment resolution was obtained after analysis of the co-influence of all five morphological features on the outcome using logistic regression method. It included three IT features significantly correlating with ST-segment resolution: Z = 1.13 − 0.51*V1 − 0.57*V2 − 0.94*V3 where V1 – IT with layered arrangement of fibrin, V2 – IT with microchannels' formation, V3 – IT with peripheral areas of infiltration by the neutrophil leukocytes (1 for the presence of the feature, 0 for its absence). “Old” IT with layered structure Conclusions Morphological features of IT in patients with acute STEMI appear to have significant influence on the primary PCI outcomes. They may be important predictors of the disease course and treatments efficacy. Further investigations of the IT peculiarities and their influences on the course of STEMI may help to improve therapy. Acknowledgement/Funding Study financial support was made by authors