Heparin-Aspirin Reperfusion Trial - HART

Description:

Heparin vs. aspirin as adjuncts to alteplase during acute MI.

Hypothesis:

The antithrombin, heparin, is more effective than aspirin in maintaining coronary patency rates after administration of rt-PA during AMI.

Study Design

Study Design:

Patients Screened: Not given
Patients Enrolled: 205
Mean Follow Up: 56 (?)
Female: 18

Patient Populations:

ST-segment elevation of at least 0.1 mV in two or more contiguous ECG leads

Exclusions:

Severe hypertension
Cerebrovascular disease
Bleeding disorders
Left bundle-branch block
Previous CABG
Recent surgery
Recent prolonged cardiopulmonary resuscitation
Premenopausal women taking oral anticoagulants
Other serious medical illnesses

Primary Endpoints:

Patency of the infarct artery after 7 to 24 hours and after 7 days.

Secondary Endpoints:

Recurrent ischemia (chest pain with ischemic ECG changes or re-elevation of plasma creatinine kinase levels) after the first hospital day and hemorrhagic events including intracerebral hemorrhage.
Decrease in the hemoglobin level of more than 1.86 mmol/L (3 g/dL) caused by bleeding at an identified site other than that involved in surgery.
Decline in the hemoglobin level of more than 2.48 mmol/L (4 g/dL) with no identified site.

Drug/Procedures Used:

rt-PA, 6-mg bolus followed by 54mg infused during the first hour, 20mg during the second hour and 5mg over each of the next four hours (total dose, 100mg).
Patients were randomly assigned to receive either oral aspirin (80mg daily) or IV heparin

Principal Findings:

Treatment with rt-PA and heparin led to a high rate of arterial patency (82%) after 7 to 24 hours.

Treatment with rt-PA and aspirin resulted in a patency rate of only 52% (P <0.0001).

Interpretation:

The HART study evaluated patency, not myocardial salvage or survival.

If vessel patency is a critical determinant of survival benefit, the potential effect of rt-PA and early heparin needs to be compared with streptokinase (SK) and early heparin [See the GISSI-2 Trial.].

There is a strong relation between activated partial thromboplastin time during the interval between thrombolysis and coronary angiography at 18 hours and the frequency of infarct-related artery patency: 45% in patients with activated partial thromboplastin time < 45 seconds at 8 and 12 hours, 88% in those with values > 45 seconds, and 95% in those with values > 60 seconds.

Vigorous antithrombotic therapy with heparin is a necessary adjunct.

References:

1. N Engl J Med 1990;323:1433-7. Final results
2. J Am Coll Cardiol 1992;20:31-5. PTT and patency

Keywords: Thrombolytic Therapy, Platelet Aggregation Inhibitors, Streptokinase, Coronary Angiography, Partial Thromboplastin Time, Heparin, Coronary Disease, Fibrinolytic Agents, Electrocardiography, Tissue Plasminogen Activator


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