Efficacy and safety of anticoagulants in the prevention of venous thromboembolism in patients with acute cerebral hemorrhage: a meta-analysis of controlled studies.

AIM: The role of anticoagulants for the prevention of venous thromboembolism in acute hemorrhagic stroke is uncertain. We performed an updated meta-analysis of studies to obtain the best estimates of the efficacy and safety of anticoagulants for the prevention of venous thromboembolism in patients with acute hemorrhagic stroke. METHODS: Using electronic and manual searches of the literature, we identified randomized and non-randomized studies comparing anticoagulants (unfractionated heparin or low-molecular-weight heparin or heparinoids) with treatments other than anticoagulants (elastic stockings, intermittent pneumatic compression or placebo) in patients with acute hemorrhagic stroke. Study outcomes included symptomatic and asymptomatic deep venous thrombosis (DVT), symptomatic and asymptomatic pulmonary embolism (PE), any hematoma enlargement or death. Risk ratios (RRs) for individual outcomes were calculated for each study and data from all studies were pooled using the Mantel-Haenszel method. RESULTS: Four studies (two randomized) involving 1000 patients with acute hemorrhagic stroke met the criteria for inclusion in this meta-analysis. Compared with other treatments, anticoagulants were associated with a significant reduction in PE (1.7% vs. 2.9%; RR, 0.37; 95% CI, 0.17-0.80; P = 0.01), a DVT rate of 4.2% compared with 3.3% (RR, 0.77; 95% CI, 0.44-1.34; P = 0.36), an increase in any hematoma enlargement (8.0% vs. 4.0%; RR, 1.42; 95% CI, 0.57-3.53; P = 0.45), and a non-significant reduction in mortality (16.1% vs. 20.9%; RR, 0.76; 95% CI, 0.57-1.03; P = 0.07). CONCLUSIONS: Our findings indicate that in patients with hemorrhagic stroke, early anticoagulation is associated with a significant reduction in PE and a non-significant reduction in mortality, with the trade-off of a non-significant increase in hematoma enlargement. These results must be taken with caution and should encourage the assessment of the clinical benefit of antithrombotic prophylaxis in patients with cerebral bleeding by properly designed clinical trials.

Cryptogenic stroke: time to determine aetiology.

Strokes that remain without a definite cause even after extensive work-up are classified as cryptogenic. These constitute about 30-40% of all strokes. Stroke aetiology may remain undetermined for the following reasons: (i) the cause of stroke is transitory or reversible and the diagnostic work-out is not therefore performed at the appropriate time; (ii) all known causes of stroke are not fully investigated; (iii) some causes of stroke remain unknown. Recent studies have challenged the previous view that cryptogenic stroke is a relatively benign cerebrovascular event, and have shown that cryptogenic stroke is associated with a higher rate of recurrence and adverse outcome at long-term follow-up. The determination of stroke aetiology is a valuable procedure to avoid the risk of stroke recurrence, especially in young patients. In this review, we discuss new evidence on the aetiology of cryptogenic stroke, specifically focusing on patients with patent foramen ovale and atheroma of the aortic arch.

Management of asymptomatic carotid stenosis in patients undergoing general and vascular surgical procedures.

Current available data do not seem to support the strategy for carotid endarterectomy prior to surgical intervention in patients with asymptomatic carotid stenosis. However, in patients with coronary artery disease, synchronous carotid endarterectomy and coronary artery bypass grafting should be considered where there is a proven surgical risk of <3% with unilateral asymptomatic stenosis >60% or bilateral carotid stenosis >75% on the same side as the most severe stenosis. Clarification of the optimal strategy requires an adequately powered, multicentre, randomised clinical trial.