Introduction and objectives: The aims of the study were to characterize myocardial edema after ST-elevation acute myocardial infarction using cardiac magnetic resonance imaging and to investigate its impact on ventricular function and its subsequent evolution.
Methods: In total, 134 patients admitted to hospital for a first ST-elevation myocardial infarction who had a patent infarct-related artery underwent cardiac magnetic resonance imaging. Cine images (at rest and with low-dose dobutamine) and edema, perfusion and viability images were acquired. Imaging was repeated after 6 months.
Results: In the first week after infarction, edema was detected in at least one segment in 96.6% of patients (4+/-2.1 segments per patient). Extensive edema (> or = 4 segments) was associated with large ventricular end-diastolic and end-systolic volumes (P< .0001), a small left ventricular ejection fraction at rest (P=.001) and with low-dose dobutamine (P=.006), a large number of segments showing hypoperfusion (P=.001) or microvascular obstruction (P=.009), a more extensive infarct (P=.017) and greater transmural extent of the infarct (P=.003). The association between the presence and extent of edema during the first week and functional, perfusion and viability variables was still observable after 6 months. No patient exhibited edema at 6 months.
Conclusions: Cardiac magnetic resonance imaging was useful for characterizing the myocardial edema that occurred after ST-elevation acute myocardial infarction. Extensive edema was associated with poor left ventricular characteristics. Edema was a transitory phenomenon that vanished within 6 months.