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Trial of secondary prevention with atenolol after transient ischemic attack or nondisabling ischemic stroke. The
Insights
Atenolol did not significantly reduce vascular events in patients after transient ischemic attack or stroke, despite lowering blood pressure. Further research is needed to confirm its efficacy in preventing major vascular events.
Area of Science:
- Cardiovascular Medicine
- Neurology
- Clinical Pharmacology
Background:
- Beta-blockers are known to prevent vascular events post-myocardial infarction and reduce blood pressure, a key stroke risk factor.
- Patients experiencing transient ischemic attack (TIA) or nondisabling ischemic stroke are at increased risk for future vascular events.
Purpose of the Study:
- To evaluate the effect of atenolol on vascular death, stroke, and myocardial infarction in patients with TIA or nondisabling ischemic stroke.
- To assess the impact of atenolol on blood pressure in this patient population.
Main Methods:
- A double-blind, placebo-controlled randomized clinical trial involving 1,473 aspirin-treated patients.
- Patients received either 50 mg of atenolol daily or a placebo, with a mean follow-up of 2.6 years.
- Primary outcomes included the combined event of vascular death, nonfatal stroke, or nonfatal myocardial infarction, and the event of fatal or nonfatal stroke.
Main Results:
- The combined outcome event occurred in 13.3% of the atenolol group versus 12.8% of the placebo group (adjusted hazard ratio, 1.00).
- The adjusted hazard ratio for fatal or nonfatal stroke was 0.82.
- Atenolol demonstrated a modest but statistically significant reduction in systolic (5.8 mm Hg) and diastolic (2.9 mm Hg) blood pressure compared to placebo. Adverse effects were more frequent in the atenolol group.
Conclusions:
- The study did not confirm or rule out the effectiveness of atenolol in preventing major vascular events in patients following TIA or nondisabling ischemic stroke.
- The modest blood pressure reduction, patient selection criteria, and limited follow-up duration may have influenced the results.
- Further investigation is warranted to clarify the role of atenolol in secondary stroke prevention.
Background And Purpose:
beta-Blockers prevent vascular events in patients after myocardial infarction and lower blood pressure, the main risk factor for stroke. Hence, we assessed the effects of atenolol on the occurrence of death from vascular causes, stroke, or myocardial infarction and on blood pressure in patients after a transient ischemic attack or nondisabling ischemic stroke.
Methods:
In a double-blind, placebo-controlled randomized clinical trial we studied the occurrence of the outcome event death from vascular causes, nonfatal stroke, or nonfatal myocardial infarction and the outcome event fatal or nonfatal stroke as well as blood pressure on follow-up. A total of 1,473 aspirin-treated patients with transient ischemic attack or nondisabling ischemic stroke were randomized to 50 mg atenolol daily or placebo. The mean follow-up was 2.6 years.
Results:
Patients on atenolol had a risk of 97/732 (13.3%) for the combined outcome event versus a risk of 95/741 (12.8%) for those on placebo (adjusted hazard ratio, 1.00; 95% confidence interval, 0.76-1.33). The adjusted hazard ratio for fatal or nonfatal stroke was 0.82 (95% confidence interval, 0.57-1.19). More patients on beta-blocker (153) reported adverse effects than on placebo (103). At the first follow-up visit after randomization (median at 4 months) systolic blood pressure in the atenolol group had dropped by 8.0 mm Hg compared with 2.2 mm Hg in the placebo group (difference, 5.8 mm Hg; 95% confidence interval, 2.9-8.6 mm Hg). For diastolic blood pressure this difference was 2.9 mm Hg (95% confidence interval, 1.5-4.4 mm Hg).
Conclusions:
Our data neither confirm nor rule out that atenolol prevents important vascular events in patients after transient ischemic attack or nondisabling ischemic stroke, given the modest effect on blood pressure, the restrictions in patient selection, and the limited number of patient-years.