OBJECTIVES: Several cardiovascular magnetic resonance imaging (CMR) techniques are used to detect microvascular obstruction (MVO) after acute myocardial infarction (AMI).
METHODS: To determine the prevalence of MVO and gain more insight into the dynamic changes in appearance of MVO, we studied 84 consecutive patients with a reperfused AMI on average 5 and 104 days after admission, using an optimised single breath-hold 3D inversion recovery gradient echo pulse sequence (IR-GRE) protocol.
RESULTS: Early MVO (2 min post-contrast) was detected in 53 patients (63%) and late MVO (10 min post-contrast) in 45 patients (54%; p = 0.008). The extent of MVO decreased from early to late imaging (4.3 +/- 3.2% vs. 1.8 +/- 1.8%, p < 0.001) and showed a heterogeneous pattern. At baseline, patients without MVO (early and late) had a higher left ventricular ejection fraction (LVEF) than patients with persistent late MVO (56 +/- 7% vs. 48 +/- 7%, p < 0.001) and LVEF was intermediate in patients with early MVO but late MVO disappearance (54 +/- 6%). During follow-up, LVEF improved in all three subgroups but remained intermediate in patients with late MVO disappearance.
CONCLUSIONS: This optimised single breath-hold 3D IR-GRE technique for imaging MVO early and late after contrast administration is fast, accurate and allows detection of patients with intermediate remodelling at follow-up. Marlon Humphrey Jersey