HONOLULU—Patients admitted to the hospital with ischemic stroke who undergo embolectomy may still have a substantially increased risk of subsequent ischemic stroke. In research presented at the 2013 International Stroke Conference, the rate ratio of ischemic stroke within one year was 426 times greater for patients with ischemic stroke who underwent embolectomy than for a control group of patients without stroke. The control group, which was intended to be representative of the general population, included hospital patients with medical and surgical conditions. Among patients who underwent embolectomy on the carotid artery, the risk of subsequent ischemic stroke within one year was 145 times greater for patients with ischemic stroke than for patients in the control cohort.
A Retrospective Review of Surgical Patients
Olena Seminog, MD, a doctoral candidate, and Michael Goldacre, FFPH, FRCP, Professor of Public Health, both at the University of Oxford, United Kingdom, searched for patients who had surgical treatment for stroke between 1999 and 2011 in a database of admissions to National Health Service hospitals in England. The researchers identified patients’ first records of surgical intervention for stroke and searched the database for any subsequent admissions or deaths from ischemic stroke for the same patients.
The investigators then compared the cohort’s rate of subsequent stroke with that of a reference cohort of patients with minor medical and surgical conditions. To ensure that the comparison between the cohorts was equivalent, the researchers stratified rates by age, sex, admission year, area of residence, and socioeconomic status.
Risk of Subsequent Stroke Declined One Year After Surgery
Compared with other procedures on the cerebral artery, embolectomy was associated with the highest risk of subsequent ischemic stroke within one year for patients with ischemic stroke. Among individuals who underwent percutaneous transluminal stenting on the cerebral artery, the risk of subsequent ischemic stroke within one year was 310 times greater for patients with ischemic stroke than for the reference cohort. Cerebral artery angioplasty was associated with the least risk of subsequent ischemic stroke within one year, compared with the other cerebral artery procedures considered.
After embolectomy, graft replacement was associated with the highest rate of subsequent ischemic stroke within one year, compared with other procedures on the carotid artery. Among individuals who underwent graft replacement, the rate of subsequent ischemic stroke within one year was nearly 39 times higher for patients with ischemic stroke than for the reference cohort. Of the surgical interventions on the carotid artery considered, endarterectomy was associated with the lowest rate of subsequent ischemic stroke within one year.
“The risk was highest within the first year after the surgery and declined substantially afterward,” said Dr. Seminog. “We found almost no difference in the risk at one to four years after the surgery and at five years or more. Prevention of stroke recurrence should be improved in stroke survivors,” she concluded.
Senior Associate Editor
Hassan AE, Chaudhry SA, Grigoryan M, et al. National trends in utilization and outcomes of endovascular treatment of acute ischemic stroke patients in the mechanical thrombectomy era. Stroke. 2012;43(11):3012-3017.
Kidwell CS, Jahan R, Gornbein J, et al. A trial of imaging selection and endovascular treatment for ischemic stroke. N Engl J Med. 2013;368(10):914-923.