ATENOLOL IN SECONDARY PREVENTION AFTER STROKE

This study investigated the effect of 50 mg atenolol in reducing the risk of death, stroke and myocardial infarction after stroke and transient ischaemic attacks (TIA). The study was designed as a Swedish multicentre, randomised, double-blind, parallel group study with randomisation stratified according to age and prognostic score. Seven hundred and twenty patients aged over 40 years who had no contraindications to beta-blockers were included within 3 weeks of a stroke or TIA, with 372 patients (mean age 70.7 years) randomised to the treatment and 348 patients (mean age 70.1 years) to the placebo group. Major strokes made up the index events in 81% of patients in the treatment and 79% of those in the placebo group. The two groups were similar in respect to baseline characteristics. The index event was classified as an ischaemic stroke in 86.8 and 86.3% of patients in the treatment and placebo groups, respectively. Side effects of atenolol and placebo caused 17 and 10% of patients to withdraw from allocated treatment. During the follow-up period (mean 28 months) 51 patients in the treatment group died compared to 60 in the placebo group [relative risk with 95% confidence interval 0.79 (0.54-1.16)] and 74 patients in the treatment group suffered a further major stroke compared to 69 in the placebo group. Twenty-six and 29 patients, respectively, suffered an acute myocardial infarction. Calculations using survival techniques and Cox's proportional hazard model indicated a reduced risk of death (21%) and myocardial infarction (7%) in the treatment group with no reduction in the risk of further stroke. None of these reductions was statistically significant. Thus the study failed to confirm a statistically significant reduction in death, stroke or myocardial infarction after major stroke or TIA by 50 mg atenolol. However, the results do not exclude a possible secondary prophylactic effect of atenolol in secondary prophylaxis after stroke and TIA.