Prehospital Thrombolytic Therapy in Patients With Suspected Acute Myocardial Infarction - EMIP

Description:

The goal of this study was to assess the safety and efficacy of prehospital thrombolytic therapy among patients with myocardial infarction (MI).

Hypothesis:

Prehospital thrombolytic administration by emergency medical personnel would reduce the time between onset of MI and reperfusion thereby, and be associated with a reduction in 30-day mortality.

Study Design

Study Design:

Patients Enrolled: 5,469
Mean Follow Up: 30 days
Mean Patient Age: Mean age 61 years
Female: 23

Patient Populations:

Patients with pain characteristic of MI lasting for at least 30 minutes, or pain lasting for less than 30 minutes but not responsive to nitrates, who were seen within six hours of the onset of symptoms and who underwent 12-lead electrocardiography

Exclusions:

Patients on oral anticoagulants (with the exception of oral antiplatelet agents); with a known bleeding diasthesis; with a history of stroke, surgery, or major trauma in the past six months; who underwent external cardiac massage for their current event; with a systolic blood pressure >200 mm Hg or a diastolic blood pressure >120 mm Hg; who were pregnant or suspected to be pregnant; or who had undergone percutaneous transluminal coronary angioplasty within the previous two weeks

Primary Endpoints:

Overall mortality at 30 days

Secondary Endpoints:

Death due to cardiac causes (arrhythmic and nonarrhythmic), ischemic or hemorrhagic stroke, other bleeding complications, death due to other vascular causes, and death due to other noncardiovascular causes

Drug/Procedures Used:

Eligible patients were randomized to receive either 30 units of anistreplase by emergency medical personnel at the time MI was diagnosed prior to hospital admission, followed by placebo after hospital admission (prehospital group), or placebo initially, followed by 30 units of anistreplase after arrival to the hospital (hospital group), in a double-blind fashion.

Concomitant Medications:

Aspirin

Principal Findings:

At 30 days, there was a nonsignificant reduction in overall mortality in the prehospital group compared to the hospital group (9.7% vs. 11.1%, p=0.08). However, death from cardiac events was significantly lower in the prehospital group (8.3% vs. 9.8%, p=0.049). The overall incidence of bleeding, ventricular fibrillation, shock, and stroke was similar between the two groups.

Interpretation:

Among patients with MI, prehospital administration of anistreplase was associated with a nonsignificant reduction in the primary endpoint of overall mortality at 30 days and a significant reduction in cardiac mortality without an increase in the overall incidence of bleeding, ventricular fibrillation, shock, and stroke.

Ten years later, the results of this study continued to be expanded upon by trials such as CAPTIM. A recent analysis of six randomized trials of prehospital lysis demonstrated a significant 16% reduction in mortality. The benefits appear to be greater among patients who present with symptoms in less than two hours.

References:

Prehospital thrombolytic therapy in patients with suspected acute myocardial infarction. The European Myocardial Infarction Project Group. N Engl J Med 1993;329:383-9.

Clinical Topics: Arrhythmias and Clinical EP, Dyslipidemia, SCD/Ventricular Arrhythmias, Lipid Metabolism, Novel Agents

Keywords: Thrombolytic Therapy, Myocardial Infarction, Stroke, Nitrates, Ventricular Fibrillation, Anistreplase, Pain, Electrocardiography


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