Randomized comparison of enoxaparin, a low-molecular-weight heparin, with unfractionated heparin adjunctive to recombinant tissue plasminogen activator thrombolysis and aspirin: second trial of Heparin and Aspirin Reperfusion Therapy (HART II).
BACKGROUND
Adjunctive unfractionated heparin (UFH) during thrombolytic therapy for acute myocardial infarction (AMI) promotes the speed and magnitude of coronary artery recanalization and reduces reocclusion. Low-molecular-weight heparins offer practical and potential pharmacological advantages over UFH in multiple applications but have not been systematically studied as adjuncts to fibrinolysis in AMI.


RESULTS
Four hundred patients undergoing reperfusion therapy with an accelerated recombinant tissue plasminogen activator regimen and aspirin for AMI were randomly assigned to receive adjunctive therapy for at least 3 days with either enoxaparin or UFH. The study was designed to show noninferiority of enoxaparin versus UFH with regard to infarct-related artery patency. Ninety minutes after starting therapy, patency rates (thrombolysis in myocardial infarction [TIMI] flow grade 2 or 3) were 80.1% and 75.1% in the enoxaparin and UFH groups, respectively. Reocclusion at 5 to 7 days from TIMI grade 2 or 3 to TIMI 0 or 1 flow and TIMI grade 3 to TIMI 0 or 1 flow, respectively, occurred in 5.9% and 3.1% of the enoxaparin group versus 9.8% and 9.1% in the UFH group. Adverse events occurred with similar frequency in both treatment groups.


CONCLUSIONS
Enoxaparin was at least as effective as UFH as an adjunct to thrombolysis, with a trend toward higher recanalization rates and less reocclusion at 5 to 7 days.
Ross
A M
AM
Cardiovascular Research Institute, Institute of Medicine, George Washington University, Washington, DC, USA. allanmross@aol.com
Molhoek
P
P
Lundergan
C
C
Knudtson
M
M
Draoui
Y
Y
Regalado
L
L
Le Louer
V
V
Bigonzi
F
F
Schwartz
W
W
de Jong
E
E
Coyne
K
K
D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use*; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000187:drug effects; D017984:Enoxaparin / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006493:Heparin / Q000009:adverse effects / Q000627:therapeutic use*; D006495:Heparin, Low-Molecular-Weight / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D020300:Intracranial Hemorrhages / Q000139:chemically induced; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology; D015425:Myocardial Reperfusion; D011994:Recombinant Proteins / Q000627:therapeutic use; D015996:Survival Rate; D015912:Thrombolytic Therapy; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D016896:Treatment Outcome
D000925:Anticoagulants; D017984:Enoxaparin; D006495:Heparin, Low-Molecular-Weight; D011994:Recombinant Proteins; D006493:Heparin; D010959:Tissue Plasminogen Activator; D001241:Aspirin