Predictors and Outcomes of Microvascular Obstruction in Cardiac Mri in Patients with St-Segment Elevation Myocardial Infarction as a Marker of No-Reflow Phenomenon

Eyas Massalha Intensive Cardiac Care Unit, Cardiology., Leviev Heart Center, Chaim Sheba Medical Center, Ramat Gan, Israel, Israel Orly Goitein Intensive Cardiac Care Unit, Cardiology., Leviev Heart Center, Chaim Sheba Medical Center, Ramat Gan, Israel, Israel Israel Mazin Intensive Cardiac Care Unit, Cardiology., Leviev Heart Center, Chaim Sheba Medical Center, Ramat Gan, Israel, Israel Elad Asher Intensive Cardiac Care Unit, Cardiology., Leviev Heart Center, Chaim Sheba Medical Center, Ramat Gan, Israel, Israel Ronen Goldkorn Intensive Cardiac Care Unit, Cardiology., Leviev Heart Center, Chaim Sheba Medical Center, Ramat Gan, Israel, Israel Fernando Chernomordik Intensive Cardiac Care Unit, Cardiology., Leviev Heart Center, Chaim Sheba Medical Center, Ramat Gan, Israel, Israel Arwa Younis Intensive Cardiac Care Unit, Cardiology., Leviev Heart Center, Chaim Sheba Medical Center, Ramat Gan, Israel, Israel Avishay Grupper Intensive Cardiac Care Unit, Cardiology., Leviev Heart Center, Chaim Sheba Medical Center, Ramat Gan, Israel, Israel Roy Beigel Intensive Cardiac Care Unit, Cardiology., Leviev Heart Center, Chaim Sheba Medical Center, Ramat Gan, Israel, Israel Shlomi Matetzky Intensive Cardiac Care Unit, Cardiology., Leviev Heart Center, Chaim Sheba Medical Center, Ramat Gan, Israel, Israel

Background: A substantial proportion of patients who undergo Primary PCI due to ST-Segment elevation myocardial infarction (STEMI) display No-Reflow (NR)” phenomenon. It characterized by inadequate myocardial tissue reperfusion despite successful reopening of infarct-related artery. Previous small studies demonstrated that Microvascular obstruction (MVO) is present on cardiac MRI (CMRI) in more than 50% of STEMI patients who are undergoing primary PCI (PPCI), and that MVO on CMRI is better correlated to NR than other angiographic parameters. MVO was also shown to be an independent predictor of LVEF and clinical outcomes.

Methods: We prospectively evaluated 135 consecutive patients, without known prior coronary disease, who underwent Primary PCI for STEMI. All patients underwent 2D-echocardiography within 48 hours of admission and CMRI at 5 ± 1 day post admission. Myocardial bio-markers (high sensitive cTnI and CPK) were determined at 0,8,12 and 24 hours post admission. Admission ECG was evaluated for sum ST-elevation and the first ECG immediately post PPCI for early ST-segment (>70%) resolution (STR). CMRI was evaluated for MVO and delayed enhancement (DE), both expressed as % of left ventricle. Patients were divided to those with and without MVO.

Results: There were no significant differences in baseline characteristics between the two study groups (age, gender and risk factors including DM). MVO was associated with lower initial angiographic TIMI grade (1.69 vs. 0.57, P<0.001). MVO was highly associated with markers of larger MI including: higher peak Troponin (25.9 vs. 77.3, P<0.001), higher CPK levels (901 vs. 2897, P<0.001). Higher Sum ST-elevations on ECG(6.98 vs. 8.85, P=0.035) and significantly lower LVEF were measured (49.48 vs. 42.66, P<0.001). Interestingly, MVO was not associated with less prevalent ST resolution. Finally, MVO was highly associated with a higher incidence of LV thrombus (0.0% vs 12%, P=0.025).

Conclusions: In patients undergoing Primary PCI for STEMI, the presence of MVO is correlated with more severe myocardial damage, a higher incidence of LV thrombus, and lower LVEF.

Presentation