Impaired myocardial tissue perfusion early after successful thrombolysis. Impact on myocardial flow, metabolism, and function at late follow-up.
BACKGROUND
Impaired tissue reperfusion after successful recanalization of an epicardial coronary artery has been documented both in animals and in patients with acute myocardial infarction. Whether this phenomenon can be demonstrated with positron emission tomography (PET) and whether it has an effect on late recovery of flow, metabolism, and function are unknown.


RESULTS
Thirty patients with an acute myocardial infarction and TIMI flow grade 3 of the infarcted vessel at 90 minutes after thrombolytic therapy were studied. Within 24 hours after thrombolysis, at 5 days and at 3 months, myocardial blood flow was measured with 13NH3. 18FDG uptake was measured at 5 days. Radionuclide left ventricular angiograms were acquired at 5 days and at 3 months. In 11 patients (37%), regional myocardial flow was severely impaired (< 50% of normally perfused myocardium) despite successful thrombolysis. No recovery of left ventricular function occurred in any of these patients at 3 months. In 12 patients (40%), intermediate flows (50% to 75% of normal) were found, with functional improvement after angioplasty only in regions with a PET mismatch. Seven patients (23%) had high flow values early after successful thrombolysis (> 75% of normal) and showed preserved regional contractile function at 3 months.


CONCLUSIONS
This study is the first demonstration with PET of impaired myocardial tissue perfusion in patients with an acute myocardial infarction after successful thrombolysis. Functional recovery of the reperfused myocardium is observed only when adequate tissue flow is restored. PET may be helpful in selecting patients in whom additional revascularization can improve recovery of left ventricular function.
Maes
A
A
Department of Nuclear Medicine, University of Leuven, Belgium.
Van de Werf
F
F
Nuyts
J
J
Bormans
G
G
Desmet
W
W
Mortelmans
L
L
D000368:Aged; D016022:Case-Control Studies; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000502:physiology; D003847:Deoxyglucose / Q000031:analogs & derivatives; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D015637:Gated Blood-Pool Imaging; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008666:Metalloendopeptidases / Q000627:therapeutic use; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism; D011446:Prospective Studies; D011994:Recombinant Proteins / Q000627:therapeutic use; D015912:Thrombolytic Therapy; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use; D014055:Tomography, Emission-Computed; D016277:Ventricular Function, Left / Q000502:physiology
D005343:Fibrinolytic Agents; D005462:Fluorine Radioisotopes; D011994:Recombinant Proteins; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose; D010959:Tissue Plasminogen Activator; D008666:Metalloendopeptidases; C022653:auR protein, Staphylococcus aureus