Hemorrhagic myocardial infarction after coronary reperfusion detected in vivo by magnetic resonance imaging in humans: Prevalence and clinical implications
K. Ochiai et al., Hemorrhagic myocardial infarction after coronary reperfusion detected in vivo by magnetic resonance imaging in humans: Prevalence and clinical implications, J CARD M RE, 1(3), 1999, pp. 247-256
With the advent of thrombolytic therapy, hemorrhagic myocardial infarction
(HMI) has been observed in experimental and human autopsy studies. However;
its clinical implications remain undetermined, because of the absence of a
reliable method to detect its presence in vivo. This study was designed to
evaluate the clinical implications of HMI detected by magnetic resonance (
MR) imaging in vivo after coronary reperfusion. Thirty-nine patients with a
cute myocardial infarction (AMI) were studied. Percutaneous transluminal co
ronary angioplasty (PTCA) was used to reopen the occluded coronary artery.
Electrocardiogram (ECG)-gated T2*-weighted gradient-echo MR imaging was per
formed to detect intramyocardial hemorrhage, using a 1.5-T magnet within 2
weeks after coronary reperfusion (average, 5.7 days). Thirteen patients (33
%) showed intramyocardial hemorrhage as a distinct hypointense zone by grad
ient-echo MR imaging and 26 patients showed homogeneous intensity consisten
t with absence of intramyocardial hemorrhage. Coronary, angiograms showed l
esser development of collateral flow in the patients with HMI than in those
without (81% vs. 37%). Infarct size, estimated 1 month after coronary repe
rfusion by thallium-201 scintigraphy, was lai-ger among patients with HMI t
han in those without (37 +/- 14% vs. 21 +/- 14%, respectively p < 0.05). Le
ft ventricular ejection fraction at 1 month follow-up showed less recovery
in patients with HMI than in those without (47 +/- 9 to 51 +/- 10%; p = 0.4
7, vs. 53 +/- 10 to 60 +/- 9%, respectively, p < 0.05). ECG-gated T2*-weigh
ted gradient-echo MR imaging offers a noninvasive means of detection of int
ramyocardial hemorrhage in patients with reperfused AMI. HMI occurred even
after primary PTCA and may be a common finding associated with severely inj
ured myocardium.