Abstract 13647: Impact and Relation of Microvascular Obstruction and Infarct Size as Predictors for Long-Term Outcome after ST-Elevation Myocardial Infarction
Background: Data on the relation of infarct size (IS) and microvascular obstruction (MO) assessed with magnetic resonance imaging (MRI) as predictors for adverse clinical outcome after ST-elevation myocardial infarction (STEMI) are inconsistent. In addition, MO and IS are correlated. Thus, the ratio of MO and IS (MO/IS) might be an even stronger predictor for outcome after STEMI which has not been investigated, yet.
Methods: STEMI patients reperfused by primary angioplasty (n=438) within 12 hours after symptom onset underwent contrast-enhanced-MRI at a median of 3 days (interquartile range [IQR] 2;4) after the index event. MO and IS were measured 15 minutes after intravenous gadolinium injection with 3D inversion recovery gradient echo sequences and were quantitatively analyzed. Clinical follow-up was conducted after 19 months (IQR 10;27). The primary endpoint was defined as a composite of death, non-fatal myocardial reinfarction and congestive heart failure.
Results: The extent of MO was moderately correlated with IS (r=0.21, p<0.001). In a first multivariate analysis including IS, ejection fraction, end-systolic and end-diastolic volume, MO was the only parameter independently associated with MACE (HR 1.03, 95%CI 1.01–1.04, p=0.001). In a second multivariable analysis including MO/IS on top of MO, IS, ejection fraction, end-systolic, and end-diastolic volume, MO/IS was identified as the strongest independent predictor for MACE (HR of 2.05; 95%CI 1.01–4.14, p=0.04).
Conclusions: In contrast to IS, MO is associated with adverse clinical outcome after STEMI even after adjustment for other MRI parameters. However, MO/IS is a more powerful predictor for long-term outcome after STEMI.
- © 2010 by American Heart Association, Inc.