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BackgroundWhether the remote myocardium of reperfused ST‐segment elevation myocardial infarction (STEMI) patients plays a part in adverse left ventricular (LV) remodeling remains unclear. We aimed to use automated extracellular volume fraction (ECV) mapping to investigate whether changes in the ECV of the remote (ECVR emote) and infarcted myocardium (ECVI nfarct) impacted LV remodeling.Methods and ResultsForty‐eight of 50 prospectively recruited reperfused STEMI patients completed a cardiovascular magnetic resonance at 4±2 days and 40 had a follow‐up scan at 5±2 months. Twenty healthy volunteers served as controls. Mean segmental values for native T1, T2, and ECV were obtained. Adverse LV remodeling was defined as ≥20% increase in LV end‐diastolic volume. ECVR emote was higher on the acute scan when compared to control (27.9±2.1% vs 26.4±2.1%; P=0.01). Eight patients developed adverse LV remodeling and had higher ECVR emote acutely (29.5±1.4% vs 27.4±2.0%; P=0.01) and remained higher at follow‐up (28.6±1.5% vs 26.6±2.1%; P=0.02) compared to those without. Patients with a higher ECVR emote and a lower myocardial salvage index (MSI) acutely were significantly associated with adverse LV remodeling, independent of T1Remote, T1Core and microvascular obstruction, whereas a higher ECVI nfarct was significantly associated with worse wall motion recovery.Conclusions ECVR emote was increased acutely in reperfused STEMI patients. Those with adverse LV remodeling had higher ECVR emote acutely, and this remained higher at follow‐up than those without adverse LV remodeling. A higher ECVR emote and a lower MSI acutely were significantly associated with adverse LV remodeling whereas segments with higher ECVI nfarct were less likely to recover wall motion.

PurposeTo investigate the performance of T 1 and T 2 mapping to detect intramyocardial hemorrhage (IMH) in ST‐segment elevation myocardial infarction (STEMI) patients treated by primary percutaneous coronary intervention (PPCI).Materials and MethodsFifty STEMI patients were prospectively recruited between August 2013 and July 2014 following informed consent. Forty‐eight patients completed a 1.5T cardiac magnetic resonance imaging (MRI) with native T 1, T 2, and T2* maps at 4 ± 2 days. Receiver operating characteristic (ROC) analyses were performed to assess the performance of T 1 and T 2 to detect IMH.ResultsThe mean age was 59 ± 13 years old and 88% (24/48) were male. In all, 39 patients had interpretable T2* maps and 26/39 (67%) of the patients had IMH ( T2* <20 msec on T2* maps). Both T 1 and T 2 values of the hypointense core within the area‐at‐risk (AAR) performed equally well to detect IMH (T 1 maps AUC 0.86 [95% confidence interval [CI] 0.72–0.99] versus T 2 maps AUC 0.86 [95% CI 0.74–0.99]; P = 0.94). Using the binary assessment of presence or absence of a hypointense core on the maps, the diagnostic performance of T 1 and T 2 remained equally good (T 1 AUC 0.87 [95% CI 0.73–1.00] versus T 2 AUC 0.85 [95% CI 0.71–0.99]; P = 0.90) with good sensitivity and specificity (T 1: 88% and 85% and T 2: 85% and 85%, respectively).ConclusionThe presence of a hypointense core on the T 1 and T 2 maps can detect IMH equally well and with good sensitivity and specificity in reperfused STEMI patients and could be used as an alternative when T2* images are not acquired or are not interpretable. Level of Evidence: 2 Technical Efficacy: Stage 2J. MAGN. RESON. IMAGING 2017;46:877–886