Tinzaparin in acute ischaemic stroke trial - TAIST

Description:

Tinzaparin in acute ischaemic stroke trial (TAIST) was a randomized, controlled, double-blind trial comparing the safety and efficacy of "medium" and "high" doses of the low molecular weight heparin tinzaparin with standard strength aspirin early after an acute ischemic stroke.

Hypothesis:

Compared with aspirin, tinzaparin given early after an acute ischemic stroke will increase the likelihood of functional independence at six months, as assessed by the modified Rankin scale.

Study Design

Study Design:

Patients Enrolled: 1,484
Mean Follow Up: Six months
Mean Patient Age: Median age 74 years
Female: 46

Patient Populations:

Acute clinical stroke syndrome, age between 18 and 90 years, able to be treated within 48 hours of stroke onset, and patient or family able to provide informed consent

Exclusions:

Intracranial hemorrhage on initial CT scan, stroke or myocardial infarction within three months, stroke complicating trauma or medical/surgical procedure, confounding neurological or psychiatric disease, uncontrolled hypertension, bleeding diathesis, severe comorbid illness, or pregnancy or lactation

Primary Endpoints:

Modified Rankin scale score of 0-2 (independence) at six months

Secondary Endpoints:

Median Rankin score at six months, death, SF-36 quality of life scores, symptomatic intracranial hemorrhage, pulmonary embolism, and deep venous thrombosis

Drug/Procedures Used:

Within 48 hours of an acute ischemic stroke, eligible patients were randomized in equal proportions to aspirin 300 mg daily, medium-dose tinzaparin (100 anti-Xa IU/kg per day), or high-dose tinzaparin (175 anti-Xa IU/kg per day). The assigned therapy was to be given until hospital discharge or up to 10 days.

Concomitant Medications:

Nontrial antiplatelet agents, anticoagulants, thrombolytics, or nonsteroidal anti-inflammatory drugs were not to be given during the initial treatment period. Use of leg compression stockings was encouraged. Antiplatelet or anticoagulant agents were also encouraged for secondary prevention after the 10-day treatment period.

Principal Findings:

The proportions with "independent" (0-2) modified Rankin scores at six months were 42.5%, 42.4%, and 41.5% for the aspirin, medium-dose tinzaparin, and high-dose tinzaparin groups, respectively (all p=NS). Compared with the aspirin group, the high-dose tinzaparin group was associated with a slight excess in symptomatic intracranial hemorrhage (0.2% vs. 1.4%, odds ratio [OR] 7.15, 95% confidence interval [CI] 1.10-163) and a slight decrease in deep vein thrombosis (1.8% vs. 0%, OR 0.0, 95% CI 0-9.29).

Interpretation:

Neither medium-dose nor high-dose tinzaparin was associated with improvements in the proportion of stroke patients achieving independent status at six months compared with aspirin. This study was in general agreement with others (i.e., TOAST, HAEST), which failed to show a benefit from low molecular weight heparin for this indication.

References:

Bath PM, Lindenstrom E, Boysen G, et al. Tinzaparin in acute ischaemic stroke (TAIST): a randomised aspirin-controlled trial. Lancet 2001;358:702-10.

Keywords: Odds Ratio, Stroke, Intracranial Hemorrhages, Platelet Aggregation Inhibitors, Heparin, Low-Molecular-Weight, Venous Thrombosis, Fibrinolytic Agents, Confidence Intervals, Informed Consent


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