Stent Versus Thrombolysis for Occluded Coronary Arteries in Patients With Acute Myocardial Infarction 1 - STOP-AMI 1

Description:

The STOP-AMI 1 trial was a randomized trial designed to compare coronary stenting plus glycoprotein IIb/IIIa inhibition using abciximab to fibrinolytic therapy with alteplase in patients with ST-elevation myocardial infarction (STEMI).

Hypothesis:

In patients with STEMI, stenting plus abciximab would result in greater myocardial salvage as assessed by myocardial salvage index on radionucleotide scintigraphy compared to fibrinolytic therapy.

Study Design

Study Design:

Patients Enrolled: 140
Mean Follow Up: 6 months
Mean Patient Age: median 60 years
Female: 24

Patient Populations:

Patients presenting within 12 hours after the onset of symptoms, chest pain for at least 20 minutes, and ST-segment elevation of at least 0.1 mV in two or more limb leads or at least 2 mV in two or more contiguous precordial leads on the surface electrocardiogram

Exclusions:

Stroke within three months; active bleeding or bleeding diathesis; trauma or major surgery within one month; suspected aortic dissection; noncompressible vascular punctures; oral anticoagulant therapy with coumarin derivatives; or severe, uncontrolled hypertension (systolic blood pressure >180 mm Hg unresponsive to therapy)

Primary Endpoints:

Myocardial salvage index, calculated as the percentage of the left ventricle that was salvaged (injection of tracer prior to therapy with imaging post-therapy compared to a second study at 10 days), divided by the percentage that was compromised by the initial perfusion defect

Secondary Endpoints:

Composite of death, reinfarction, and stroke within six months after randomization

Drug/Procedures Used:

Two arms:

1) Stent + IIb/IIIa: Stenting with Guidant Multi-link stent, with additional 2500 U of heparin and abciximab (0.25 mg/kg bolus followed by infusion of 10 mcg/min). Post-percutaneous coronary intervention regimen was ticlodipine 250 mg bid and aspirin.

2) Intravenous fibrinolytic: 15 mg bolus of alteplase, followed by 0.75 mg/kg infusion for 30 minutes (max 50 mg), and 0.5 mg/kg for 60 minutes (max 35 mg). Aspirin and heparin were given post-fibrinolytic therapy.

Concomitant Medications:

Aspirin (500 mg) and heparin (5000 U) prior to initiation of assigned therapy

Principal Findings:

A total of 140 patients were enrolled (71 in the stenting/abciximab arm and 69 in the alteplase arm). The two arms were well-balanced, with a significantly longer time to initiation of therapy in the stenting/abciximab arm (65 vs. 30 minutes after admission, p<0.001), and a median time from onset of symptoms to treatment of 150 minutes in both arms.

Initial and 10-day radionucleotide scans were obtained in 88% of patients. The size of the initial perfusion defect was similar in both groups, but the final size of the infarct was significantly smaller among patients in the stent/abciximab group versus the alteplase group (14.3% vs. 19.4%, p=0.02).

There was a greater degree of myocardial salvage in the stent/abciximab group (16.1% vs. 7.4% of the left ventricle, p<0.001). The salvage index was significantly greater with stenting/abciximab than with alteplase (0.57 vs. 0.26, p<0.001). The composite endpoint of death, reinfarction, or stroke at 30 days was lower in the stent/abciximab group versus the alteplase group (7.0% vs. 13.0%, p=0.02).

Interpretation:

In this 140-patient trial in STEMI, stenting with abciximab resulted in improvements in myocardial salvage and final infarct size at 10 days when compared to alteplase. There was also a decrease in the incidence of the combined endpoint of death, reinfarction, and stroke between groups (lower rates in the stenting/abciximab arm); however, the study was not adequately powered to detect a difference in clinical outcomes. It is unclear from the primary analysis of this study how longer times to treatment would affect the results.

References:

Schomig AA, Kastrati J, Dirschinger J, et al. Coronary stenting plus platelet glycoprotein IIb/IIIa blockade compared with tissue plasminogen activator in acute myocardial infarction. Stent versus Thrombolysis for Occluded Coronary Arteries in Patients with Acute Myocardial Infarction Study Investigators. N Engl J Med 2000;343:385-91.

Clinical Topics: Anticoagulation Management, Dyslipidemia, Invasive Cardiovascular Angiography and Intervention, Lipid Metabolism

Keywords: Thrombolytic Therapy, Myocardial Infarction, Stroke, Platelet Aggregation Inhibitors, Heparin, Immunoglobulin Fab Fragments, Fibrinolytic Agents, Electrocardiography, Stents, Percutaneous Coronary Intervention, Chest Pain, Tissue Plasminogen Activator, Heart Ventricles, Platelet Glycoprotein GPIIb-IIIa Complex


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