Early myocardial edema after acute myocardial infarction is stable and not bimodal in humans - Evidence from a large CMR multicenter study.

BACKGROUND

Experimental data reported a temporal pattern of myocardial edema following acute myocardial infarction (AMI). Therefore, the aim of this study was to assess the time course of myocardial edema in a large population of patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

Myocardium at risk (MAR), infarct size (IS) and myocardial salvage index (MSI) were compared according to the time between infarction and cardiovascular magnetic resonance (CMR) imaging in a large multicenter STEMI cohort (n=795). CMR scans performed >8days (>192h) after AMI were excluded (n=23). Scans performed within 8days were reported at time-points 12-24h, 24-36h, 36-48h, and days 3 to 8 (192h).

RESULTS

MAR/MSI and IS could be assessed in 693 and 755 patients, respectively. The extent of MAR over the first week after ischemia/reperfusion showed a slight rise and fall (p=0.029 in one-way analysis of variance). However, analysis of IS demonstrated a similar trend over time (p=0.026). Post-hoc testing did not reveal significant differences between particular time periods for both MAR and IS. A stable edematous reaction was also observed between 12-24h, 24-36h, 36-48h and up to 8days after infarction in a more detailed analysis. MSI did not show statistically significant variations (p=0.147). Multivariate regression analysis did not identify the time of CMR acquisition as a predictor of MAR (p=0.709), IS (p=0.810) or MSI (p=0.916).

CONCLUSION

These data do not confirm a temporal pattern of myocardial edema over the first week after AMI in humans.