Patients with stroke are at high risk for subsequent vascular events, including recurrent stroke (highest risk), myocardial infarction, and death from vascular causes. The latest article in our Clinical Practice series reviews recommended strategies to reduce the risk of a subsequent stroke in patients with a history of transient ischemic attack (TIA) or stroke.
Worldwide, stroke is the second most common cause of death (ischemic heart disease being the most common) and is a leading cause of acquired disability. In some regions, the combined incidence of stroke and transient ischemic attacks (TIAs) exceeds the incidence of coronary vascular events. More than 85% of fatal strokes occur in low- and middle- income countries. Patients with stroke are at high risk for subsequent vascular events, including recurrent stroke (highest risk), myocardial infarction, and death from vascular causes. Because the risk of stroke is highest in the early period after the acute event, prompt initiation of tailored prevention strategies is essential.
• What is the most important modifiable risk factor in primary and secondary prevention of stroke?
Hypertension is the most important modifiable risk factor in both primary and secondary prevention of stroke. Observational studies and clinical trials support blood-pressure reduction for secondary prevention in most patients, regardless of the initial blood-pressure level. Data are lacking to determine the optimal blood-pressure target and extent of lowering, and guidelines recommend that treatment be individualized, but benefits have been linked to absolute blood-pressure reductions of approximately 10/5 mm Hg.
• What are current secondary stroke prevention guidelines with respect to cholesterol management?
Secondary-prevention guidelines recommend treatment for patients with a low-density lipoprotein (LDL) cholesterol level of 100 mg per deciliter (2.6 mmol per liter) or higher, with the aim of reducing the level by at least 50% or achieving a target level of less than 70 mg per deciliter (1.8 mmol per liter). In the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) study, a placebo-controlled trial involving patients with a recent TIA or stroke and baseline LDL cholesterol levels of 100 to190 mg per deciliter (2.6 to 4.9 mmol per liter), those randomly assigned to atorvastatin (at a dose of 80 mg per day) had significant reductions in the risks of stroke and all cardiovascular events (absolute risk reductions, 2.2 percentage points and 3.5 percentage points, respectively, over a period of 5 years).
Morning Report Questions
Q: What are the guidelines for antiplatelet therapy in secondary stroke prevention?
A: Current guidelines indicate that aspirin alone, clopidogrel, and aspirin plus dipyridamole are all acceptable first-line options in secondary stroke prevention. Randomized trials have shown no benefit, and increased hemorrhagic risks, with the combined use of clopidogrel and aspirin as compared with clopidogrel alone or aspirin alone for long-term secondary prevention after stroke. In the Secondary Prevention of Small Subcortical Strokes trial, which is evaluating antiplatelet therapy with aspirin plus clopidogrel versus aspirin alone, as well as two approaches to blood- ressure lowering, the combination antiplatelet therapy was recently terminated prematurely owing to excess hemorrhages and deaths.
Q: When is carotid endarterectomy (CEA) versus carotid stenting indicated?
A: Carotid endarterectomy is indicated for the treatment of patients with a history of TIA or nondisabling ischemic stroke who have high-grade (70 to 99%) carotid stenosis or, in selected cases, moderate (50 to 69%) stenosis. Early intervention, within 2 weeks after the onset of symptoms, is now recommended, given evidence that the benefits of surgery rapidly diminish with increasing time since the ischemic event. The use of carotid-artery stenting as an alternative to carotid endarterectomy is more controversial. Carotid-artery stenting is less invasive than endarterectomy and is associated with a more rapid recovery and a low risk of cranial-nerve palsies. However, studies have shown that the periprocedural risks (chiefly death and recurrent stroke within 30 days) are significantly higher with carotid-artery stenting than with carotid endarterectomy. In patients older than 70 years of age, carotid endarterectomy appears to be superior to carotid-artery stenting, whereas in patients 70 years of age or younger, carotid-artery stenting (performed by interventionists with acceptable complication rates) appears to be a reasonable alternative to carotid endarterectomy.