RELATIONSHIP BETWEEN PROGRESSIVE MICROVASCULAR DAMAGE AND INTRAMYOCARDIAL HEMORRHAGE IN PATIENTS WITH REPERFUSED ANTERIOR MYOCARDIAL-INFARCTION - MYOCARDIAL CONTRAST ECHOCARDIOGRAPHIC STUDY
T. Asanuma et al., RELATIONSHIP BETWEEN PROGRESSIVE MICROVASCULAR DAMAGE AND INTRAMYOCARDIAL HEMORRHAGE IN PATIENTS WITH REPERFUSED ANTERIOR MYOCARDIAL-INFARCTION - MYOCARDIAL CONTRAST ECHOCARDIOGRAPHIC STUDY, Circulation, 96(2), 1997, pp. 448-453
Background Recent studies indicated that ischemic microvascular damage
may be reversible or progressive after coronary reflow. Intramyocardi
al hemorrhage is a phenomenon that reflects severe microvascular injur
y. We examined the relationship between temporal changes in microvascu
lar perfusion patterns detected by myocardial contrast echocardiograph
y (MCE) and intramyocardial hemorrhage detected by magnetic resonance
imaging (MRI) in patients with acute myocardial infarction (AMI). Meth
ods and Results The study population consisted of 24 patients with ant
erior AMI. All patients underwent MCE shortly after reflow and in the
chronic stage (a mean of 31 days after reflow). Wall motion score (WMS
) was determined as the sum of 16 segmental scores (dyskinetic/akineti
c=3 to normal=0) at days 1 and 31. Gradient-echo acquisition and gadol
inium-DTPA-enhanced spin-echo MRI were performed within 10 days after
reflow. In MCE shortly after reflow, 16 patients (67%) showed contrast
enhancement and the other 8 patients (33%) showed a sizable contrast
defect. In the chronic stage, a persistent contrast defect was observe
d in 7 of 8 patients with a contrast defect shortly after reflow. Cons
istent contrast enhancement was observed in 12 of 16 patients (75%) wi
th contrast enhancement shortly after reflow, indicating that a contra
st defect newly appeared in 4 patients (25%). Intramyocardial hemorrha
ge was detected in 9 patients (38%): 5 of 7 patients with a persistent
contrast defect and in all 4 patients with a new appearance of a cont
rast defect during the chronic stage. The patients without hemorrhage
showed a significant improvement in WMS compared with patients with he
morrhage at day 31 (5+/-5 versus 19+/-6, P<.0005). Conclusions These r
esults suggest that irreversible microvascular damage to the ischemic
myocardium may cause intramyocardial hemorrhage after reflow, associat
ed with impaired recovery of left ventricular function. Contrast enhan
cement within the risk area shortly after reflow does not necessarily
indicate long-term microvascular salvage.