Abortion of acute ST segment elevation myocardial infarction after reperfusion: incidence, patients' characteristics, and prognosis.
OBJECTIVE
To study the incidence and patient characteristics of aborted myocardial infarction in both prehospital and in-hospital thrombolysis.


METHODS
Retrospective, controlled, observational study.


METHODS
Two cities in the Netherlands, one with prehospital thrombolysis, one with in-hospital treatment.


METHODS
475 patients with suspected acute ST elevation myocardial infarction treated before admission to hospital, 269 patients treated in hospital.


METHODS
Aborted myocardial infarction, defined as the combination of subsiding of cumulative ST segment elevation and depression to < 50% of the level at presentation, together with a rise of creatine kinase of less than twice the upper normal concentration. A stepwise regression analysis was used to test independent predictors for aborted myocardial infarction.


RESULTS
After correction for "unjustified" thrombolysis, 17.1% of the 468 prehospital treated patients and 4.5% of the 264 in-hospital treated patients fulfilled the criteria for aborted myocardial infarction. There was no difference in age, sex, risk factors, haemodynamic status, and infarct location of aborted myocardial infarction compared with established myocardial infarction. Time to treatment was shorter in the patients with aborted myocardial infarction (86 versus 123 minutes, p = 0.05). A shorter time to treatment, lower ST elevation at presentation, and higher incidence of preinfarction angina were independent predictors for aborted myocardial infarction. Aborted myocardial infarction had a 12 month mortality of 2.2%, significantly less than the 11.6% of established myocardial infarction.


CONCLUSIONS
Prehospital thrombolysis is associated with a fourfold increase of aborted myocardial infarction compared with in-hospital treatment. A shorter time to treatment, a lower ST elevation, and a higher incidence of preinfarction angina were predictors of aborted myocardial infarction.
Lamfers
E J P
EJ
Department of Cardiology, Canisius-Wilhelmina Hospital, Nijmegen, Netherlands. ejp.lamfers@inter.nl.net
Hooghoudt
T E H
TE
Hertzberger
D P
DP
Schut
A
A
Stolwijk
P W J
PW
Verheugt
F W A
FW
D017023:Coronary Angiography / Q000706:statistics & numerical data; D004562:Electrocardiography; D004632:Emergency Medical Services / Q000706:statistics & numerical data; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000453:epidemiology; D009426:Netherlands / Q000453:epidemiology; D011379:Prognosis; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D015912:Thrombolytic Therapy / Q000379:methods*; D013997:Time Factors
D005343:Fibrinolytic Agents