Thromboprophylaxis in acute ischaemic stroke: how can we PREVAIL?

Validation of risk stratification schemes for predicting stroke and thromboembolism in patients with atrial fibrillation: nationwide cohort study

OBJECTIVES

To evaluate the individual risk factors composing the CHADS(2) (Congestive heart failure, Hypertension, Age ≥ 75 years, Diabetes, previous Stroke) score and the CHA(2)DS(2)-VASc (CHA(2)DS(2)-Vascular disease, Age 65-74 years, Sex category) score and to calculate the capability of the schemes to predict thromboembolism.

DESIGN

Registry based cohort study.

SETTING

Nationwide data on patients admitted to hospital with atrial fibrillation. Population All patients with atrial fibrillation not treated with vitamin K antagonists in Denmark in the period 1997-2006.

MAIN OUTCOME MEASURES

Stroke and thromboembolism.

RESULTS

Of 121,280 patients with non-valvular atrial fibrillation, 73,538 (60.6%) fulfilled the study inclusion criteria. In patients at "low risk" (score = 0), the rate of thromboembolism per 100 person years was 1.67 (95% confidence interval 1.47 to 1.89) with CHADS(2) and 0.78 (0.58 to 1.04) with CHA(2)DS(2)-VASc at one year's follow-up. In patients at "intermediate risk" (score = 1), this rate was 4.75 (4.45 to 5.07) with CHADS(2) and 2.01 (1.70 to 2.36) with CHA(2)DS(2)-VASc. The rate of thromboembolism depended on the individual risk factors composing the scores, and both schemes underestimated the risk associated with previous thromboembolic events. When patients were categorised into low, intermediate, and high risk groups, C statistics at 10 years' follow-up were 0.812 (0.796 to 0.827) with CHADS(2) and 0.888 (0.875 to 0.900) with CHA(2)DS(2)-VASc.

CONCLUSIONS

The risk associated with a specific risk stratification score depended on the risk factors composing the score. CHA(2)DS(2)-VASc performed better than CHADS(2) in predicting patients at high risk, and those categorised as low risk by CHA(2)DS(2)-VASc were truly at low risk for thromboembolism.

Venous thromboembolism prophylaxis and treatment in patients with acute stroke and traumatic brain injury

PURPOSE OF REVIEW

Patients with acute stroke and traumatic brain injury are at risk to develop venous thromboembolism. This review analyzes the available literature to propose guidelines for the prevention and treatment of venous thromboembolism in these groups of patients.

RECENT FINDINGS

In acute ischemic stroke, low-dose low-molecular-weight heparin has the best benefit-risk ratio to prevent venous thromboembolism. Patients with primary intracerebral hemorrhage and traumatic brain injury should receive intermittent pneumatic compression, followed by low-dose low-molecular-weight heparin or unfractioned heparin 3-4 days after stroke onset or 24 h after injury or surgery, respectively, and after cessation of bleeding. Concerning treatment, in patients with deep-vein thrombosis lower doses of heparin are indicated to prevent pulmonary embolism, and a vena cava filter should be considered. In patients with pulmonary embolism, treatment could be more aggressive, because of a high mortality risk.

SUMMARY

Adequate prevention of venous thromboembolism with intermittent pneumatic compression or pharmacological prophylaxis is important. The best treatment of venous thromboembolism remains unclear. In case of pulmonary embolism, more aggressive treatment is warranted.