Correlation of serial cardiac magnetic resonance imaging parameters with early resolution of ST-segment elevation after primary percutaneous coronary intervention.

BACKGROUND The aim of the present study was to determine whether the parameters of cardiac magnetic resonance imaging (CMRI) might correlate with early ST-segment resolution (STR) after primary percutaneous coronary intervention (PCI) in ST-elevation myocardial infarction (STEMI). METHODS AND RESULTS CMRI was performed in 45 STEMI patients (age: 56.6+/-13.0 years) at 8.2+/-8.0 days (early phase) and 3.3+/-1.1 months (late phase) after successful PCI. CMRI parameters were compared between 2 groups: > or = 70% STR (group 1, n = 21) and < 70% STR (group 2, n = 24). Both groups had similar baseline characteristics, except for a higher frequency of > or = 2 myocardial blush grade and shorter pain-to-balloon time in group 1. Early-phase CMRI showed that persistent microvascular obstruction (PMO) (38.1% vs 91.7%, p < 0.001) occurred less frequently and the percent infarct mass against total left ventricular (LV) mass (17.7+/-8.7% vs 29.1+/-13.4%, p = 0.001) was smaller in group 1. Late-phase CMRI revealed a significant increase in LV end-diastolic volume (-1.5+/-8.7 vs 14.5+/-25.5 ml, p = 0.026) and reduced ejection fraction (55.0+/-9.9% vs 47.8+/-11.1%, p = 0.027) in group 2. CONCLUSIONS CMRI demonstrated that early STR might be related to PMO and infarct size, and predicts LV dysfunction and adverse LV remodeling. Also, early-phase CMRI findings are comparable to late-phase CMRI in association with early STR.