Comparison of effectiveness of enoxaparin versus unfractionated heparin to reduce silent and clinically apparent acute myocardial infarction in patients presenting with non-ST-segment elevation acute coronary syndrome.
Electrocardiographic (ECG) estimates of myocardial infarct size based on the Selvester ECG score have been shown to predict mortality and left ventricular function after acute myocardial infarction (AMI). This score has also been used to identify not clinically apparent AMI ("silent" AMI) and to determine treatment effect, suggesting it could serve as a clinical trial end point. The objective of this study was to compare the rate of silent AMI as measured by the Selvester QRS score in patients with a non-ST-segment elevation acute coronary syndrome treated with enoxaparin versus intravenous unfractionated heparin who were participating in a continuous ECG monitoring substudy of the Efficacy and Safety of Subcutaneous Enoxaparin in Non-Q-wave Coronary Events study (ESSENCE) and INTegrelin and Enoxaparin Randomized Assessment of acute Coronary syndrome Treatment trial (INTERACT). Enoxaparin was associated with a 56% relative risk decrease in silent AMI at 96 hours compared with unfractionated heparin (2.7% vs 6.1% p = 0.03). Similarly, enoxaparin decreased Holter-detected myocardial ischemia compared with unfractionated heparin (18.7% vs 35.9%, p = 0.03). In conclusion, enoxaparin significantly decreased the composite of silent AMI or clinical AMI and death at 1 year (9.3% vs 21%, p = 0.0001).
Jolly
Sanjit
S
Terrence Donnelly Heart Centre, Division of Cardiology, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada.
Tan
Mary
M
Mendelsohn
Aurora
A
Fitchett
David
D
Armstrong
Paul W
PW
Langer
Anatoly
A
Goodman
Shaun G
SG
D000925:Anticoagulants / Q000627:therapeutic use*; D015716:Electrocardiography, Ambulatory / Q000187:drug effects; D017984:Enoxaparin / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006493:Heparin / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D011859:Radiography; D013577:Syndrome; D016896:Treatment Outcome
D000925:Anticoagulants; D017984:Enoxaparin; D006493:Heparin