Early contrast-enhanced MRI predicts late functional recovery after reperfused myocardial infarction.
BACKGROUND
We have observed 3 abnormal patterns on contrast-enhanced MRI early after reperfused myocardial infarction (MI): (1) absence of normal first-pass signal enhancement (HYPO), (2) normal first pass signal followed by hyperenhanced signal on delayed images (HYPER), or (3) both absence of normal first-pass enhancement and delayed hyperenhancement (COMB). This study examines the association between these patterns in the first week after MI and late recovery of myocardial contractile function by use of magnetic resonance myocardial tissue tagging.


RESULTS
Seventeen patients (14 men) with a mean age of 53+/-12 years were studied after a reperfused first MI. Contrast-enhanced images were acquired immediately after bolus administration of gadolinium and 7+/-2 minutes later. Tagged images were acquired at weeks 1 and 7. Circumferential segment shortening (%S) was measured in regions displaying HYPER, COMB, or HYPO contrast patterns and in remote regions (REMOTE) at weeks 1 and 7. At week 1, %S was depressed in HYPER, COMB, and HYPO (9+/-8%, 7+/-6%, and 5+/-4%, respectively) and were less than REMOTE (18+/-6%, P<0.003). However, in HYPER, %S improved at week 7 from 9+/-8% to 18+/-5% (P<0.001 versus week 1). In contrast, HYPO did not improve significantly (5+/-4% to 6+/-3%, P=NS) and COMB tended to improve 7+/-6% to 11+/-6% (P=0.06).


CONCLUSIONS
HYPER has partially reversible dysfunction and represents predominantly viable myocardium. COMB shows borderline improvement and likely contains an admixture of viable and necrotic myocardium. HYPO shows little functional improvement at 7 weeks, presumably because of irreversible myocardial damage.
Rogers
W J
WJ
Division of Cardiology, Department of Medicine, Allegheny General Hospital, Pittsburgh, PA 15212, USA.
Kramer
C M
CM
Geskin
G
G
Hu
Y L
YL
Theobald
T M
TM
Vido
D A
DA
Petruolo
S
S
Reichek
N
N
D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D005500:Follow-Up Studies; D005682:Gadolinium; D006801:Humans; D007700:Kinetics; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000534:rehabilitation; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000534:rehabilitation; D015425:Myocardial Reperfusion / Q000009:adverse effects / Q000534:rehabilitation*; D015428:Myocardial Reperfusion Injury / Q000175:diagnosis* / Q000534:rehabilitation; D015588:Observer Variation; D011237:Predictive Value of Tests; D013599:Systole; D016277:Ventricular Function, Left