NEW ORLEANS—Hyperlipidemia was associated with poor outcomes after endovascular therapies for acute ischemic stroke, but using a statin appeared to speed neurologic recovery after these procedures, according to the results of separate studies presented at the 2008 International Stroke Conference.
Among risk factors found to be significantly associated with poor outcome after intra-arterial thrombolysis or percutaneous mechanical embolectomy for the treatment of acute ischemic stroke, hyperlipidemia was the only modifiable one, said Lucas Restrepo, MD, Clinical Instructor at the Comprehensive Stroke and Vascular Neurology Program, University of California, Los Angeles, and lead investigator of the studies.
“About two-thirds of acute ischemic stroke patients who undergo percutaneous revascularization procedures do not have excellent outcomes (meaning little or no disability). Even excellent angiographic results may not always translate into a satisfactory clinical recovery,” stated Dr. Restrepo. “Therefore, there is a need to understand whether any modifiable factors are associated with poor outcomes after endovascular procedures to treat them aggressively.”
Hyperlipidemia and Stroke Treatment
The researchers examined three databases that included a total of 142 acute ischemic stroke patients admitted to the University of California Medical Center from 1992 to 2006 and who were treated within 12 hours with intra-arterial thrombolysis or percutaneous mechanical embolectomy. Intra-arterial thrombolysis was performed in 79% of the patients and percutaneous mechanical embolectomy in 22%.
After adjustment for covariates, the researchers found that three risk factors emerged as significant predictors of poor outcomes at three months: age, stroke severity based on the NIH Stroke Scale (NIHSS) score on admission, and a history of hyperlipidemia. Every 50-mg/dL increment in total cholesterol level resulted in a 64% decrease in the odds of achieving a Rankin score of 0 or 1 at three months. Hyperlipidemia was associated with a 4.6-unit increase on the NIHSS.
Stroke severity on admission (per the NIHSS) and previous use of oral anticoagulation were significantly associated with an increased risk of systemic hemorrhage, whereas initial stroke severity and blood glucose levels greater than 200 mg/dL were associated with intracerebral hemorrhage.
Benefits of Statins for Stroke
In a separate study of the same registry of patients, Dr. Restrepo’s group analyzed the impact of statins on outcomes after endovascular procedures. “Emergency endovascular procedures for acute ischemic stroke carry a risk of intracerebral hemorrhage, and statins also carry a small risk of causing brain hemorrhage, so we wondered about the safety of statin use in persons undergoing these procedures,” said Dr. Restrepo.
Twenty-two patients used a statin (mostly low-dose atorvastatin) before their stroke, all but one of whom continued therapy after hospital admission. An additional 45 patients began using a statin after their procedure.
When the investigators adjusted for age and comorbidities, they found that statin use before the procedure doubled the likelihood of having excellent functional status after stroke. Also, statin use both before and after stroke tripled the likelihood of excellent functional status, although neither difference was statistically significant.
The chance of having a greater than 6.5-point improvement in NIHSS score at seven days poststroke or at discharge was higher in those who were on statins before and after their stroke, compared with patients not receiving a statin. Statin use was also associated with a 69% reduced risk of symptomatic intracerebral hemorrhage, although not significant.
“Statin use seemed to be protective against intracerebral hemorrhage in this cohort of patients, although the trend did not reach statistical significance,” asserted Dr. Restrepo. “Our study does suggest that it’s safe to use a statin when undergoing an endovascular procedure for acute ischemic stroke treatment.”