Abstract 409: Incidence and Prognostic Impact of Persistent Microvascular Obstruction as Assessed by Cardiac Magnetic Resonance in the Setting of Non ST Segment Elevation Myocardial Infarction
Purpose: To investigate the incidence and the prognostic significance of microvascular obstruction (MO) and persistent microvascular obstruction (PMO) as assessed by Cardiac Magnetic Resonance (CMR) in patients with Non ST Elevation Myocardial Infarction (NSTEMI).
Methods: CMR was performed in 61 patients with following successfully reperfused first NSTEMI. First-pass images were performed to evaluate extent of MO and Late Gadolinium-enhanced images to assess PMO and Infarct size (IS). Major Adverse Cardiac Events (MACE) were collected at 1-year follow-up.
Results: MO and PMO were found in 28 (46%) and 17 (28%) patients, respectively. Fifteen patients had MACE at one year, including 4 cardiac death. Age (p=0.020), GRACE risk score (p=0.005), IS (odds ratio [OR] 95% confidence interval [CI]: 1.08[1.01–1.15], p=0.020), multivessel disease (p=0.011), EDV Index (p=0.003), ESV Index (p=0.010), presence of MO (OR[95%CI]: 4.69[1.29 –17.07], p=0.019) and presence of PMO (OR[95%CI]: 18.33[4.39 –76.64], p<0.001) were univariately associated with MACE. By multivariate analysis, only the presence of PMO (OR[95%CI] 11.5 [2.4–55.7]; p=0.003) was predictors of MACE. Figure⇓ shows Kaplan-Meier event-free survival curve in patient stratified by presence of MO and presence of PMO.
Conclusion: PMO is very common in NSTEMI patients even after successful reperfusion and is associated with a dramatically higher risk of cardiovascular events, beyond established prognostic markers. The reduction of PMO is a major goal which needs optimal use of therapeutic strategies for reperfusion and also during post-interventional management.