Stent vs. Thrombolysis for Occluded Coronary Arteries in Patients With Acute Myocardial Infarction 2 - STOP-AMI 2

Description:

The STOP-AMI 2 trial was a randomized trial designed to compare coronary stenting to fibrinolytic therapy with alteplase, both combined with abciximab, 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 combined fibrinolytic therapy with alteplase plus abciximab.

Study Design

Study Design:

Patients Screened: 307
Patients Enrolled: 162
Mean Follow Up: 6 months
Mean Patient Age: mean of 61 in both arms
Female: 25

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, at least 2 mV in two or more contiguous precordial leads, or new left bundle branch block 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 7-14 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, as well as other major adverse cardiac events and bleeding complications

Drug/Procedures Used:

The two arms were:

• Stenting: Stenting (Guidant Multi-link stent recommended), with additional 2500 U of heparin.

• Intravenous fibrinolytic: 15 mg bolus of alteplase, followed by a 35 mg infusion for 60 minutes. Heparin was given for 24 hours post-fibrinolytic therapy.

Concomitant Medications:

Abciximab 0.25 mg/kg bolus followed by 0.125 mcg/kg/min infusion (to maximum of 10 mcg/min) for 12 hours, aspirin 500 mg, and heparin 60 U/kg (max 5000 U) prior to initiation of assigned therapy; and clopidogrel 75 mg qd for four weeks, and aspirin 100 mg bid indefinitely

Principal Findings:

A total of 162 patients were enrolled (81 in the stenting/abciximab arm and 81 in the alteplase/abciximab arm). The two arms were generally well-balanced, with a significantly longer time to initiation of therapy in the stenting/abciximab arm (75 vs. 35 minutes after admission).

Initial and 7-14 day follow-up radionucleotide scans (median 11 days) were obtained in almost 90% 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/abciximab group (8.0% vs. 16.0%, p=0.01).

There was a greater degree of myocardial salvage in the stent/abciximab group (13.6% vs. 8.0% of the left ventricle, p=0.007) and the salvage index was significantly greater with stenting/abciximab than with alteplase/abciximab (0.60 vs. 0.41, p=0.001).

The composite endpoint of death, reinfarction, or stroke at six months was nonsignificantly less in the stent/abciximab group vs. the alteplase/abciximab group (8.6% vs. 18.5%, p=0.06).

Interpretation:

Among patients with STEMI, a strategy of stenting plus abciximab was associated with improvements in myocardial salvage and final infarct size at 11 days when compared to combined fibrinolytic therapy with abciximab. There was also a nonsignificant 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, and only five patients underwent percutaneous coronary intervention following initial therapy in the combined fibrinolytic arm. In the initial STOP-AMI 1 trial, stenting plus abciximab was compared to fibrinolytic therapy without IIb/IIIa inhibition, and stenting/abciximab was associated with greater myocardial salvage.

References:

Kastrati A, Mehilli J, Dirschinger J, et al., for the Stent versus Thrombolysis for Occluded Coronary Arteries in Patients With Acute Myocardial Infarction (STOPAMI-2) Study. Myocardial salvage after coronary stenting plus abciximab versus fibrinolysis plus abciximab in patients with acute myocardial infarction: a randomised trial. Lancet 2002;359:920-5.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Dyslipidemia, Invasive Cardiovascular Angiography and Intervention, EP Basic Science, Lipid Metabolism

Keywords: Thrombolytic Therapy, Myocardial Infarction, Stroke, Follow-Up Studies, Platelet Aggregation Inhibitors, Heparin, Immunoglobulin Fab Fragments, Fibrinolytic Agents, Electrocardiography, Stents, Percutaneous Coronary Intervention, Chest Pain, Bundle-Branch Block, Tissue Plasminogen Activator, Heart Ventricles


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