Myocardial Infarction Triage and Intervention Project--phase II - MITI II


Prehospital thrombolytics for mortality in acute myocardial infarction.


Prehospital initiation of thrombolytic therapy might provide the opportunity to treat a large proportion of patients within the first 2 hours of symptom onset.

Study Design

Study Design:

Patients Screened: Not given
Patients Enrolled: 360

Patient Populations:

<75 years old who were alert, oriented, and had ongoing chest discomfort of suspected cardiac origin for >15 minutes and <6 hours
Systolic blood pressure >80 and <180 mm Hg
Diastolic blood pressure <120 mmHg and a systolic blood pressure difference between arms <20 mmHg (to minimize the possibility of aortic dissection)


Chest pain >6 hours from symptom onset
Age >75 years
Presence of complicating illnesses that were considered to be contraindications for prehospital thrombolytic therapy

Primary Endpoints:

Survival and event-free survival, defined as survival free of death, MI, or hospitalization for angina, congestive heart failure, or revascularization.

Drug/Procedures Used:

Aspirin or recombinant tissue plasminogen activator, either before or after hospital arrival.

Concomitant Medications:

IV sodium heparin

Principal Findings:

Two-year survival was 89% for prehospital- and 91% for hospital-treated patients (p = 0.46).
Event-free survival at 2 years was 56% and 64% for prehospital- and hospital-treated patients, respectively (p = 0.42).
In patients treated < 70 minutes from symptom onset, 2-year survival was 98%, and it was 88% for those treated later (p = 0.12).
Two-year event-free survival was 65% for patients treated early and 59% for patients treated later (p = 0.80).


In this trial, poorer long-term survival was associated with advanced age, history of congestive heart failure, and coronary artery bypass surgery performed before the index hospitalization, but not with time to treatment.


1. Am J Cardiol 1996;78:497-502. Final results

Clinical Topics: Cardiac Surgery, Dyslipidemia, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Cardiac Surgery and Heart Failure, Lipid Metabolism, Acute Heart Failure

Keywords: Thrombolytic Therapy, Myocardial Infarction, Heart Failure, Disease-Free Survival, Blood Pressure, Fibrinolytic Agents, Tissue Plasminogen Activator, Coronary Artery Bypass

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