Randomized Angiographic Trial of Recombinant Tissue-Type Plasminogen Activator (Alteplase) in Myocardial Infarction - RAAMI

Description:

RAAMI was a multicenter, randomized, open-label trial of rt-PA 100 mg given over three hours versus rt-PA given over 90 minutes in patients with ST elevation myocardial infarction (STEMI).

Hypothesis:

Rt-PA given over 90 minutes will be associated with improved vessel patency compared with a three-hour infusion time.

Study Design

Study Design:

Patients Enrolled: 281
Mean Follow Up: Hospital discharge
Mean Patient Age: <75
Female: 25

Patient Populations:

Men and women with age <76 with chest pain consistent with coronary ischemia lasting ≥30 minutes but <6 hours unresponsive to nitroglycerine therapy, and ST elevation on ECG of at least 1 mm in two contiguous leads

Exclusions:

Known pregnancy, any history of stroke, uncontrolled hypertension, any bleeding disorder, previous coronary artery bypass grafting, recent surgery, or trauma

Primary Endpoints:

TIMI grade flow through infarct-related vessel at 90 minutes

Secondary Endpoints:

Bleeding events and death

Drug/Procedures Used:

Patients with acute STEMI were randomized to rt-PA 100 mg over three hours or over 90 minutes. All patients underwent coronary angiography at 60 to 90 minutes after infusion initiation.

Concomitant Medications:

All patients were treated with aspirin (80 mg PO qd) and intravenous heparin (5000 U bolus followed by 1000 U/h titrated to partial thromboplastin time 1.5-2 times normal).

Principal Findings:

A total of 281 patients were randomized. At baseline, the groups were well matched in terms of age, gender, and location of infarct. One hundred seventy-three patients had angiography within 60 minutes, and 250 patients had angiography within 90 minutes.

Rates of TIMI grade II or III flow were significantly higher at 60 minutes in the 90-minute dosing arm (76% vs. 63%, p=0.03). At 90 minutes, rates of TIMI grade II or III flow were similar between groups (81% for three-hour arm vs. 77% for 90-minute arm, p=0.21). There were no significant differences between groups in rates of recurrent ischemia, chronic heart failure, stroke, bleeding, or death.

Interpretation:

Among patients with STEMI, accelerated dosing over 90 minutes of rt-PA was associated with similar but earlier reperfusion than the same dose given over three hours without an increase in adverse events. Despite the earlier reperfusion, this trial does not, however, give evidence that this earlier reperfusion is linked with improved clinical outcomes. However, the trial was relatively small and not powered for clinical events.

References:

Carney RJ, Murphy GA, Brandt TR, et al. Randomized angiographic trial of recombinant tissue-type plasminogen activator (alteplase) in myocardial infarction. RAAMI Study Investigators. J Am Coll Cardiol 1992;20:17-23.

Keywords: Thrombolytic Therapy, Myocardial Infarction, Stroke, Coronary Angiography, Chest Pain, Heart Failure, Electrocardiography, Tissue Plasminogen Activator


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