The salvaged area at risk in reperfused acute myocardial infarction as visualized by cardiovascular magnetic resonance.
OBJECTIVE
We aimed to characterize the tissue changes within the perfusion bed of infarct-related vessels in patients with acutely reperfused myocardial infarction (MI) using cardiovascular magnetic resonance (CMR).


BACKGROUND
Even in successful early revascularization, intermittent coronary artery occlusion affects the entire perfusion bed, also referred to as the area at risk. The extent of the salvaged area at risk contains prognostic information and may serve as a therapeutic target. Cardiovascular magnetic resonance can visualize the area at risk; yet, clinical data have been lacking.


METHODS
We studied 92 patients with acute MI and successful reperfusion 3 +/- 3 days after the event and 18 healthy control subjects. Breath-hold T2-weighted and contrast-enhanced ("late enhancement") CMR were used to visualize the reversible and the irreversible myocardial injury, respectively.


RESULTS
All reperfused infarcts consistently revealed a pattern with both reversibly and irreversibly injured tissue. In contrast to the infarcted area, reversible damage was always transmural, exceeding the infarct in its maximal extent by 16 +/- 11% (absolute difference of the area of maximal infarct expansion 38 +/- 15% vs. 22 +/- 10%; p < 0.0001). None of the controls had significant T2 signal intensity abnormalities.


CONCLUSIONS
In patients with reperfused MI, CMR visualizes both reversible and irreversible injury. This allows for quantifying the extent of the salvaged area after revascularization as an important parameter for clinical decision-making and research.
Friedrich
Matthias G
MG
Stephenson Cardiovascular Magnetic Resonance Centre at the Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, University of Calgary, Alberta, Canada. matthias.friedrich@ucalgary.ca
Abdel-Aty
Hassan
H
Taylor
Andrew
A
Schulz-Menger
Jeanette
J
Messroghli
Daniel
D
Dietz
Rainer
R
D000328:Adult; D016022:Case-Control Studies; D004562:Electrocardiography; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D015425:Myocardial Reperfusion; D009204:Myocardial Revascularization; D011379:Prognosis; D018570:Risk Assessment
D019786:Gadolinium DTPA