BANGKOK – Statin therapy, even when initiated only upon hospitalization for acute ischemic stroke, was associated with a striking reduction in the risk of early poststroke symptomatic seizure in a large observational study.
Bruce Jancin/MDedge News
Dr. Soichiro Matsubara
Using propensity-score matching to control for potential confounders, use of a statin during acute stroke management was associated with a “robust” 77% reduction in the risk of developing a symptomatic seizure within 7 days after hospital admission, Soichiro Matsubara, MD, reported at the International Epilepsy Congress.
This is an important finding because early symptomatic seizure (ESS) occurs in 2%-7% of patients following an acute ischemic stroke. Moreover, an Italian meta-analysis concluded that ESS was associated with a 4.4-fold increased risk of developing poststroke epilepsy (Epilepsia. 2016 Aug;57[8]:1205-14), noted Dr. Matsubara, a neurologist at the National Cerebral and Cardiovascular Center in Suita, Japan, as well as at Kumamoto (Japan) University.
He presented a study of 2,969 consecutive acute ischemic stroke patients with no history of epilepsy who were admitted to the Japanese comprehensive stroke center, of whom 2.2% experienced ESS. At physician discretion, 19% of the ESS cohort were on a statin during their acute stroke management, as were 55% of the no-ESS group. Four-fifths of patients on a statin initiated the drug only upon hospital admission.
Strokes tended to be more severe in the ESS group, with a median initial National Institutes of Health Stroke Scale score of 12.5, compared with 4 in the seizure-free patients. A cortical stroke lesion was evident upon imaging in 89% of the ESS group and 55% of no-ESS patients. Among ESS patients, 46% had a cardiometabolic stroke, compared with 34% of the no-ESS cohort. Mean C-reactive protein levels and white blood cell counts were significantly higher in the ESS cohort as well. Their median hospital length of stay was 25.5 days, versus 18 days in the no-ESS group, Dr. Matsubara said at the congress sponsored by the International League Against Epilepsy.
Of the 76 ESSs that occurred in 66 patients, 37% were focal awareness seizures, 35% were focal to bilateral tonic-clonic seizures, and 28% were focal impaired awareness seizures.
In a multivariate analysis adjusted for age, sex, body mass index, stroke subtype, and other potential confounders, statin therapy during acute management of stroke was independently associated with a 56% reduction in the relative risk of ESS. In contrast, a cortical stroke lesion was associated with a 2.83-fold increased risk.
Since this wasn’t a randomized trial of statin therapy, Dr. Matsubara and his coinvestigators felt the need to go further in analyzing the data. After extensive propensity score matching for atrial fibrillation, current smoking, systolic blood pressure, the presence or absence of a cortical stroke lesion, large vessel stenosis, and other possible confounders, they were left with two closely comparable groups: 886 statin-treated stroke patients and an equal number who were not on statin therapy during their acute stroke management. The key finding: The risk of ESS was reduced by a whopping 77% in the patients on statin therapy.
The neurologist observed that these new findings in acute ischemic stroke patients are consistent with an earlier study in a U.S. Veterans Affairs population, which demonstrated that statin therapy was associated with a significantly lower risk of new-onset geriatric epilepsy (J Am Geriatr Soc. 2009 Feb;57[2]:237-42).
As to the possible mechanism by which statins may protect against ESS, Dr. Matsubara noted that acute ischemic stroke causes toxic neuronal excitation because of blood-brain barrier disruption, ion channel dysfunction, altered gene expression, and increased release of neurotransmitters. In animal models, statins provide a neuroprotective effect by reducing glutamate levels, activating endothelial nitric oxide synthase, and inhibiting production of interleukin-6, tumor necrosis factor-alpha, and other inflammatory cytokines.
Asked about the intensity of the statin therapy, Dr. Matsubara replied that the target was typically an LDL cholesterol below 100 mg/dL.
He reported having no financial conflicts regarding the study, conducted free of commercial support.
SOURCE: Matsubara S et al. IEC 219, Abstract P002.