The RT-PA-APSAC Patency Study - TAPS

Description:

Accelerated alteplase vs. anistreplase for angiographic patency in acute MI.

Hypothesis:

The effects of this front-loaded administration of rt-PA vs. those obtained with APSAC on early patency and reocclusion of infarct-related coronary arteries in patients with acute myocardial infarction (AMI).

Study Design

Study Design:

Patients Screened: Not given
Patients Enrolled: 421
Mean Follow Up: 21 days
Mean Patient Age: 57
Female: 18.7
Mean Ejection Fraction: Left ventricular ejection fraction at follow-up angiography was essentially identical in both the rt-PA and APSAC treatment groups.

Patient Populations:

Typical symptoms of AMI and ST-segment elevations in at least 2 of the 12 leads of the standard ECG: >2mm in limb leads and >3 mm in precordial leads, or >1mm in 2 limb leads and ST-segment depression >2mm in >2 precordial leads.

Exclusions:

Contraindications to thrombolytic therapy
Any other conditions posing an increased risk of bleeding during fibrinolysis
Inability to give informed consent
Previous infarction in the same site
Previous coronary artery bypass surgery
Previous treatment with streptokinase or APSAC

Primary Endpoints:

Reocclusion

Secondary Endpoints:

Death, reinfarction, angiographic assessment of left ventricular ejection fraction, peak serum creatine kinase.

Drug/Procedures Used:

Heparin, 5000 U IV bolus; and rt-PA, 15mg IV bolus then 50mg over 30 minutes and 35mg over 60 minutes; or heparin, 5000 U IV bolus; followed by APSAC, 30mg IV bolus over 5 minutes.

Concomitant Medications:

Aspirin, 100 mg/day

Principal Findings:

Coronary angiography 90 min after the start of treatment revealed a patent infarct-related artery (Thrombolysis in Myocardial Infarction [TIMI] grade 2 or 3) in 84.4% of 199 patients given rt-PA vs. 70.3% of 202 patients given APSAC (p = 0.0007).

Early reocclusion within 24 to 48 h was documented in 10.3% of 174 patients given rt-PA vs. 2.5% of 163 patients given APSAC. Late reocclusion within 21 days was observed in 2.6% of 152 patients given rt-PA vs. 6.3% of 159 patients given APSAC.

There were 5 in-hospital deaths (2.4%) in the rt-PA group and 17 deaths (8.1%) in the APSAC group (p = 0.0095).

The reinfarction rate was 3.8% in the rt-PA group vs. and 4.8% in the APSAC group.

Peak serum creatine kinase and left ventricular ejection fraction at follow-up angiography were essentially identical in both treatment groups.

There were more bleeding complications after APSAC (45% vs. 31%, p = 0.0019).

Two intracranial hemorrhages (0.9%) occurred in each group; one of these was fatal (in the APSAC group).

Interpretation:

Early and sustained patency seem to be of major importance for a favorable outcome. Front loaded administration of 100 mg of rt-PA yields a significantly higher early patency rate in the infarct-related artery in comparison with that achieved with APSAC. Although more early reocclusions occur after rt-PA than after APSAC treatment, hospital reinfarction rates are similar. The statistically significant difference in hospital mortality between the two patient groups needs to be confirmed by a further trial with mortality as a primary endpoint.

References:

1. J Am Coll Cardiol 1992;19:885-91. Final results

Keywords: Myocardial Infarction, Creatine Kinase, Hospital Mortality, Follow-Up Studies, Heparin, Fibrinolytic Agents, Electrocardiography, Intracranial Hemorrhages, Coronary Angiography, Stroke Volume, Anistreplase, Coronary Vessels, Tissue Plasminogen Activator, Hemorrhage


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