P2711Prevalence of collateral circulation and its importance on the development of reperfusion injury in patients with acute myocardial infarction with ST-segment elevation

Abstract Prevalence of collateral circulation and its importance on the development of reperfusion injury in patients with acute myocardial infarction with st segment elevation treated with primary percutaneous coronary angioplasty Introduction In myocardial infarction with ST-segment elevation, early restoration of flow is the most important objective, but there is a possibility that reperfusion may induce ischemia-reperfusion injury. There is little information about the relationship of collateral circulation and reperfusion damage in patients with infarction, which is the reason for our study. Objective: To determine the prevalence of collateral circulation and its importance in the development of microvascular occlusion and intramyocardial hemorrhage evaluated by magnetic resonance imaging in patients with acute myocardial infarction with ST-segment elevation. Methods Observational, analytical study, retrospective cohort. Methods From March 2008 to April 2017, 359 patients were included and they were over 18 years of age with acute myocardial infarction with ST-segment elevation undergoing primary angioplasty who had magnetic resonance imaging. It was classified into 2 groups of patients: Group 1 (309 patients, without collateral circulation) and group 2 (50 patients, with collateral circulation). The presence or absence of collateral circulation was determined by coronary angiography and reperfusion injury (microvascular obstruction and intramyocardial hemorrhage) was evaluated by magnetic resonance. The x2 test was used to compare the categorical variables and the Mann-Whitney U test for continuous numerical variables. Results Of 359 patients, 50 (13.9%) patients had collateral circulation. The presence of reperfusion damage by magnetic resonance was compared. Patients in group 1 had reperfusion injury in 73.8% and group 2, 70.0% (p: 0.57). Presence or absence of reperfusion injury in patients with and without collateral circulation No Collateral circulation Collateral circulation “p” value n=309 (%) n=50 (%) Reperfusion inury 0.57 No 81 (26.2%) 15 (30.0%) Yes 228 (73.8%) 35 (70.0%) Microvascular Obstruction 0.59 No 81 (26.4%) 15 (30.0%) Yes 226 (73.6%) 35 (70.0%) Myocardial Hemorrhage 0.24 No 189 (61.4%) 35 (70.0%) Yes 119 (38.6%) 15 (30.0%) Conclusions In the present study it is demonstrated that the presence of collateral circulation did not influence the reperfusion damage, so the collateral circulation does not protect the myocardium