P5554Microvascular obstruction in cardiac magnetic resonance is an independent predictor of major adverse cardiovascular events in patients with ST-segment elevation myocardial infarction

Purpose: The aim of the study was to determine prognostic value of microvascular obstruction (MVO) evaluated by cardiac magnetic resonance imaging (CMR) in comparison to the other predictive parameters in patients with ST-elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (pPCI). Material and methods: 85 STEMI patients treated by pPCI within 12 hours after symptom onset had an evaluation of CMR within three days. Markers of necrosis were measured every 8 hours from the admission to the hospital. Electrocardiography (Selvester and Aldrich score) were assessed at the admission, after pPCI and before CMR and echocardiography (WMSI) within the first day after pPCI. CMR was performed on the 1.5T system within 96 hours after pPCI. Morphology and function of LV was estimated by steady-state free precession (SSFP). To evaluate the infarct size and MVO, late gadolinium enhancement (LGE) sequence was performed 10–15 minutes after administration of gadobutrol. Infarct size was defined as area above 50% of the maximal signal intensity within LGE (FWMH – full-width half maximum). MVO was described as the area of absence or hyperenhancement of myocardium surrounded by LGE. IS and MVO were determined by planimetry and summation of discs method. All patients were observed 24 months to evaluate major adverse cardiovascular events (MACE). The primary endpoint was defined as a composite of death, myocardial reinfarction, coronary reintervention and congestive heart failure.