Stroke Alert: A Review of Current Clinical Stroke Literature

By Matthew E. Fink, MD, Interim Chair and Neurologist-in-Chief, Director, Division of Stroke & Critical Care Neurology, Weill Cornell Medical College and New York Presbyterian Hospital

Endovascular Coiling Has Less Morbidity and Mortality Than Surgical Clipping for Unruptured Brain Aneurysms

Source: Brinjikji W, et al. Effect of age on outcomes of treatment of unruptured cerebral aneurysms. A study of the National Inpatient Sample 2001-2008. Stroke 2011;42:1320-1324.

Neurologists at the Mayo Clinic reviewed the morbidity and mortality of patients who underwent treatment for unruptured brain aneurysms, Based on data from the National Inpatient Sample (20% of all inpatient admissions to nonfederal hospitals in the United States) from 2001-2008, and compared outcomes based on type of treatment (coiling vs clipping) and age, in order to assess the impact of these variables on outcome. Four age strata were evaluated — younger than 50 years, 50 to 64 years, 65 to 79 years, and 80 years and older.

Patients younger than 50 years undergoing coiling had lower morbidity rates compared to patients who underwent clipping (3.5% vs 8.1%; P < 0.0001), but there was no mortality difference (0.6% vs 0.6%). Patients between 50 and 64 years undergoing coiling had lower morbidity (4.0% vs 13.7%) and mortality (0.5% vs 1.1%) compared to clipping, as did the groups from 65 to 79 years (morbidity = 6.9% vs 26.8%; mortality = 0.8% vs 2.0%), and aged 80 or older (morbidity = 9.8% vs 33.5%; mortality = 2.4% vs 21.4%). Overall, patients treated with coiling had less morbidity and mortality than those treated with clipping, and this difference became more pronounced with increasing age.

Recurrent Stroke Risk After Complete Internal Carotid Artery Occlusion is Low

Source: Persoon S, et al. Symptomatic internal carotid artery occlusion: Long-term follow-up study. J Neurol Neurosurg Psychiaty 2011;82:521-526.

Persoon and investigators from utrecht, nether-lands, prospectively followed 117 consecutive patients with transient or moderately disabling cerebral or retinal ischemia associated with ICA occlusion, presenting between 1995 and 1998, and followed them until 2008. The authors determined the risk of recurrent stroke and other vascular events, and performed adjusted, univariate regression analysis to determine significant riskfactors. Mean age was 61 years, 80% were male, 22 un- derwent endarterectomy for contralateral ICA stenosis, 16 underwent extracranial/intracranial bypass surgery, and patients were followed for a median time of 10.2 years.

Recurrent ischemic stroke occurred in 23 patients, for an annual stroke rate of 2.4% (95% CI = 1.5-3.6). Significant risk factors for recurrent ischemic stroke were age (HR = 1.07), cerebral rather than retinal symptoms (HR = 8.0), recurrent symptoms after the occlusion (HR = 4.4), limb-shaking TIA on presentation (HR = 7.5), prior history of stroke (HR = 2.8), and leptomeningeal collaterals visible on angiography (HR = 5.2). The composite of any vascular event occurred in 57 patients, for an annual rate of 6.4%. The long-term risk of recurrent ischemic stroke after ICA occlusion is much lower than all vascular events combined.

Mechanical Endovascular Therapy is Therapeutic Option for Acute Isolated Middle Cerebral Artery Occlusion

Source: Rouchaud A, et al. Outcomes of mechanical endovascular therapy for acute ischemic stroke. A clinical registry study and systematic review. Stroke 2011;42:1289-1294.

Intravenous thrombolysis with recombinant tissue plasminogen activator (rtPA) is the standard of care for acute ischemic stroke, but its success in recanalizing large artery occlusions, specifically middle cerebral artery (MCA) occlusions, is poor. Mechanical endovascular therapies are being used around the world, but there are no randomized clinical trials comparing these therapies with intravenous rtPA to analyze stroke outcomes. Investigators at Bichat University Hospital in Paris, France, analyzed their data from a prospective clinical registry and identified 47 patients with acute stroke who were treated with MET. In addition, they surveyed the literature and identified 31 previous studies involving a total of 1066 subjects. In a pooled meta-analysis of clinical outcomes, including their own data, the overall recanalization rate was 79% (95% confidence interval [CI] = 73-84). Pooled data revealed an estimate of 40% (95% CI = 34-46) for favorable outcome, 28% (95% CI = 23-33) for mortality, and 8% (95% CI = 6-10) for symptomatic hemorrhage. Favorable outcome increased with the use of thrombolysis (OR = 1.99) and with an increasing proportion of patients with isolated MCA occlusion (OR per 10% increase = 1.14). MET has an acceptable profile for safety and efficacy in acute ischemic stroke, particularly in those with MCA occlusion.

Carotid Endarterectomy for Asymptomatic Carotid Artery Sstenosis Reduces Long-term Risk of Stroke for Patients 75 Years of Age and Younger

Source: Halliday A, et al. 10-year stroke prevention after successful carotid endarterectomy for asymptomatic stenosis (ACST-1): A multicentre randomized trial. Lancet 2010;376:1074-1084.

In 2004, the asymptomatic carotid surgery trial 1 (ACST-1) reported the medium-term benefits of carotid endarterectomy (CEA) for patients who had asymptomatic carotid artery stenosis (> 60%) for a period up to 5 years. The early (30-day) risk of stroke or death from surgery was 3% in that trial. The authors now provide a long-term follow-up study of 3120 patients who were randomly assigned to CEA or medical therapy between 1993 and 2003, and followed up until death or for a median among survivors of 9 years.

Excluding perioperative events and non-stroke mortality, stroke risks (CEA vs medical) were 4.1% vs 10.0% at 5 years and 10.8% vs 16.9% at 10 years, with a ratio of stroke incidence rates of 0.54 (P < 0.0001). Sixty-two vs 104 had a disabling or fatal stroke, and 37 vs 84 others had a non-disabling stroke. Medications were similar in both groups, and were predominantly antithrombotic and antihypertensive medications. Benefits were significant for those on or not on lipid-lowering medications, and both for men and women up to age 75 years at entry, but not for older patients.