Heparin in Acute Embolic Stroke Trial - HAEST


Heparin in Acute Embolic Stroke Trial (HAEST) was a randomized trial comparing the effects of aspirin and dalteparin, a low molecular weight heparin, in patients with atrial fibrillation (AF) and acute ischemic stroke.


In patients with AF, dalteparin will be safe and superior to aspirin in the prevention of recurrent strokes during the first 14 days after an acute ischemic stroke.

Study Design

Study Design:

Patients Screened: 7,570
Patients Enrolled: 449
Mean Follow Up: Three months
Mean Patient Age: 44-98 years (median 80)
Female: 55

Patient Populations:

Adults with ECG-documented AF (on admission or within the previous two years) presenting within 30 hours of an acute ischemic stroke. Hemorrhagic stroke was excluded by computed tomography.


1) Clear indication for anticoagulant therapy.
2) Clear contraindication against anticoagulant therapy.
3) Scandinavian Stroke Scale score <8.
4) Persistent uncontrolled hypertension (systolic blood pressure [BP] >200 mm Hg or diastolic BP >110 mm Hg).
5) Life expectancy <6 months from comorbid disease.
6) Pregnancy or breast feeding.

Primary Endpoints:

Recurrent ischemic stroke within 14 days

Secondary Endpoints:

1) Cerebral hemorrhage within 14 days.
2) Progression of initial stroke symptoms within 48 hours.
3) Death from any cause within 14 days.
4) Neurologic status at 14 days and three months.

Drug/Procedures Used:

Within 30 hours of stroke onset, patients were randomized to aspirin (160 mg per day) or dalteparin (100 IU/kg subcutaneously twice a day), given in double-blind, double-dummy fashion. Study therapies were continued until hospital discharge, or 14 days (range 11-17 days).

Concomitant Medications:

Patients with a clear indication for (or contraindication against) anticoagulant therapy were excluded from the trial.

Principal Findings:

Recurrent strokes within 14 days of the index event occurred in 19/244 (8.5%) patients in the dalteparin group versus 17/225 (7.5%) patients in the aspirin group (odds ratio 1.13, 95% confidence interval 0.57-2.24, p=NS). Likewise, no significant differences were observed between dalteparin and aspirin groups in the secondary endpoints of cerebral hemorrhage (11.6% vs. 14.2%, p=0.41), progression of symptoms (10.7% vs. 7.6%, p=0.26), or all-cause mortality (9.4% vs. 7.1%, p=0.40). Similar numbers of patients enjoyed complete recovery at three months (22.8% vs. 21.3%, p=0.84).


Following ischemic strokes in patients with AF, treatment with low-dose aspirin or dalteparin was associated with similar rates of recurrent ischemic stroke, cerebral hemorrhage, progression of symptoms, death, and full recovery. The findings of this study are consistent with those of prior studies, which also failed to show significant clinical improvement among stroke patients treated with unfractionated heparin, low molecular weight heparin, or danaparoid.


Berge E, Abdelnoor M, Nakstad PH, Sandset PM. Low molecular-weight heparin versus aspirin in patients with acute ischaemic stroke and atrial fibrillation: a double-blind randomised study. HAEST Study Group. Heparin in Acute Embolic Stroke Trial. Lancet 2000;355:1205-10.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Noninvasive Imaging, Anticoagulation Management and Atrial Fibrillation, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Stroke, Platelet Aggregation Inhibitors, Tomography, Heparin, Dalteparin, Atrial Fibrillation, Electrocardiography, Cerebral Hemorrhage

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