Combination therapy with abciximab reduces angiographically evident thrombus in acute myocardial infarction: a TIMI 14 substudy.
BACKGROUND
Use of abciximab in combination with administration of thrombolytics has been shown to improve epicardial and microvascular coronary blood flow in acute myocardial infarction (AMI). As a potential mechanism, we hypothesized that combination therapy would reduce angiographically evident thrombus (AET) and would increase lumen diameter compared with thrombolytic monotherapy.


RESULTS
Patients who received combination therapy in TIMI 14 (low-dose thrombolytic plus abciximab, n=732) were compared with patients who received thrombolytic monotherapy without abciximab in the TIMI 4, 10A, 10B, and 14 trials (n=1662). Thrombus burden was assessed 90 minutes after treatment, and quantitative angiography was performed in an angiographic core laboratory by investigators blinded to treatment assignment. The frequency of AET was reduced in patients who received abciximab combination therapy compared with thrombolytic monotherapy (26.6% versus 35.4%, P<0.001). Similar findings were observed when the analysis was restricted to patients with patent arteries (14.7% versus 20.8%, P=0.001). Residual percent diameter stenosis at 90 minutes was also improved in the abciximab therapy group both in patent arteries (64.6+/-16.6 versus 68.3+/-14.8, P<0.001) and between patent and occluded arteries (69.3+/-19.5 versus 73.8+/-17.9, P<0.001). The absence of AET was associated with an increased frequency of >70% ST-segment resolution by 90 minutes (37.2%, 110/296 versus 18.9%, 54/286, P<0.001).


CONCLUSIONS
Compared with thrombolytic monotherapy, combination therapy with abciximab reduces AET, which in turn is associated with reduced residual stenosis and improved ST-segment resolution in AMI. These data provide a pathophysiological link between platelet inhibition, reduced thrombus, and improvements in both epicardial and microvascular perfusion in AMI.
Gibson
C M
CM
Harvard Clinical Research Institute, Boston, Massachusetts, USA.
de Lemos
J A
JA
Murphy
S A
SA
Marble
S J
SJ
McCabe
C H
CH
Cannon
C P
CP
Antman
E M
EM
Braunwald
E
E
D000077284:Abciximab; D000368:Aged; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects / Q000503:physiopathology; D004359:Drug Therapy, Combination; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000503:physiopathology; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D013927:Thrombosis / Q000473:pathology / Q000517:prevention & control*; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D005343:Fibrinolytic Agents; D007140:Immunoglobulin Fab Fragments; D010975:Platelet Aggregation Inhibitors; D010959:Tissue Plasminogen Activator; D000077284:Abciximab