A dynamic model forecasting myocardial infarct size before, during, and after reperfusion therapy: an ASSENT-2 ECG/VCG substudy.
OBJECTIVE
Serial forecasts of final myocardial infarct (MI) size during fibrinolytic treatment (Rx) of ST-elevation MI would allow the identification of high-risk patients with a predicted major loss of viable myocardium, at a point when treatment may still be modified. We investigated a model for such forecasting, using time and the ECG.


RESULTS
We collected 234 patients with ST-elevation MI, without signs of previous MI, bundle branch block, or hypertrophy. MI size was determined by the Selvester score and was "forecasted" at: admission with patients stratified by delay time and an ECG acuteness score into three groups (EARLY, DISCORDANT, and LATE); 90 min after Rx by > or =70% ST-recovery or not and occurrence of "reperfusion peaks"; 4 h after Rx by ST re-elevations. EARLY patients had smaller final infarct sizes than LATE (9.4 vs. 20%, P=0.01). EARLY patients with > or =70% ST-recovery without a reperfusion peak had smaller infarct sizes than those with (3.1 vs. 12.5%, P=0.001). EARLY patients without ST re-elevations had smaller infarct sizes (1.5%) than those with some (9%) or many re-elevations (12%), P<0.001.


CONCLUSIONS
Final infarct size can be forecasted using delay time and serial ECGs. Serially updated forecasts seem especially important when both clock-time and initial ECG- signs indicate earliness.
Johanson
Per
P
Division of Cardiology, Sahlgrenska University Hospital/Ostra, SE-41685 Göteborg, Sweden. pj@hjl.gu.se
Fu
Yuling
Y
Goodman
Shaun G
SG
Dellborg
Mikael
M
Armstrong
Paul W
PW
Krucoff
Mitchell W
MW
Wallentin
Lars
L
Wagner
Galen S
GS
D000368:Aged; D004562:Electrocardiography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000473:pathology* / Q000503:physiopathology; D011379:Prognosis; D012720:Severity of Illness Index; D015912:Thrombolytic Therapy; D013997:Time Factors; D014672:Vectorcardiography