Prognostic Value of Microvascular Damage Determined by Cardiac Magnetic Resonance in Non ST-Segment Elevation Myocardial Infarction

OBJECTIVES: To compare 2 cardiac magnetic resonance (CMR) techniques for the evaluation of the prognostic significance of microvascular damage after non ST-segment elevation myocardial infarction (NSTEMI). MATERIALS AND METHODS: CMR was performed at 3T in 61 patients within the week following their first NSTEMI. A first-pass saturation-recovery gradient-echo perfusion sequence was started during the infusion of contrast material to evaluate the extent of microvascular obstruction (MO) during the first 2 minutes after injection (MO(<2 min)) and between 3 and 5 minutes thereafter (MO(3 min), MO(4 min), MO(5 min)). Ten minutes after injection, late gadolinium-enhanced images were obtained using a phase sensitive inversion recovery sequence to assess persistent MO (PMO) and infarct size. Major adverse cardiac events (MACE) were collected at 1-year follow-up. RESULTS: MO(<2 min) and PMO were found in 28 of 61 and 17 of 61 patients, respectively. About 15 patients had MACE at 1 year, including 4 cardiac deaths. In univariate logistic regression analysis, age (odds ratio [OR], 1.07, P = 0.020), infarct size (OR, 1.08, P = 0.020), multivessel disease (OR, 5.08, P = 0.011), end diastolic volume (OR, 1.04, P = 0.003), end systolic volume (OR, 1.03, P = 0.010), MO from < 2 to 5 minutes postinjection (P < 0.05) and PMO (OR, 18.33, P < 0.001) were significantly associated with the outcome. In multivariate analysis, only PMO remained an independent predictor of MACE. CONCLUSION: Microvascular damage assessed by CMR is associated with a dramatically higher risk of cardiovascular events in NSTEMI patients. Moreover, our data suggest that PMO as assessed on late gadolinium-enhanced images might have a higher prognostic value than MO evaluated on first-pass images.