Cerebrovascular Disease

Is a controlled trial of long-term oral anticoagulants in patients with stroke and non-rheumatic atrial fibrillation worthwhile?

A controlled randomised trial large enough to assess the value of anticoagulating stroke patients in atrial fibrillation would be difficult to conduct in the UK and the results would be applicable to only a small proportion of stroke patients. It would be more worthwhile to organise a trial that also assessed the value of other treatments that are simpler and applicable to all stroke patients. A trial that assessed the value of aspirin and beta-blockers against control in all stroke patients would not cost much more than one restricted to comparing anticoagulants against control in patients with stroke and atrial fibrillation but would provide information of more relevance to the management of patients with stroke in the UK.

Antifibrinolytic treatment in subarachnoid hemorrhage

We enrolled 479 patients with subarachnoid hemorrhage in a multicenter, randomized, double-blind, placebo-controlled trial to determine whether treatment with the antifibrinolytic agent tranexamic acid improves outcome by preventing rebleeding. At three months there was no statistical difference between the outcomes in the tranexamic acid group and the control group. Of the 173 patients who died, 84 had received tranexamic acid and 89 placebo (95 per cent confidence interval for the difference in mortality rate, -6 to 11 per cent). Similarly, when analysis was restricted to patients with an angiographically demonstrated aneurysm, there was no significant difference between the groups. This absence of effect was not due to a lack of antifibrinolytic action, since the rate of rebleeding was reduced from 24 per cent in the control group to 9 per cent in the tranexamic acid-treated group (chi-square = 18.07, P less than 0.001), but resulted from a concurrent increase in the incidence of ischemic complications (15 per cent in the control group and 24 per cent in the tranexamic acid group; chi-square = 8.07, P less than 0.01). We conclude that until some method can be found to minimize ischemic complications, tranexamic acid is of no benefit in patients with subarachnoid hemorrhage.

Relation of atrial fibrillation and high haematocrit to mortality in acute stroke

Clinical and laboratory abnormalities and the presence of atrial fibrillation on admission were examined in relation to hospital mortality in a retrospective study of the 320 patients with acute stroke admitted to a medical unit in a 5-year period. Of clinical factors, only increasing age and the presence of coma were associated with mortality. Atrial fibrillation, present in 25% of all patients, was associated with an increased mortality in patients aged 60-79 years (67% vs 44%, p less than 0.01). In patients under 75 years the mortality associated with raised haematocrit (0.50 or more), present in 11% of all patients, was more than twice as high as it was in those with lower haematocrit (71% vs 31%, p less than 0.005). Other laboratory variables associated with a high mortality were increased levels of mean red cell volume, white cell count, erythrocyte sedimentation rate, globulin, and blood urea and creatinine; and decreased levels of albumin. The high prevalence of and increased mortality associated with atrial fibrillation and raised haematocrit in stroke patients indicate the need for further studies of stroke prevention and treatment in these patients.