For many patients, cholesterol-lowering statin drugs can reduce the risk of strokes as well as heart attacks. But in a review article, Loyola University Health System neurologists caution that statins may not be appropriate for cetain categories of patients who are at risk for stroke.
The article, by Dr. Murray Flaster and colleagues, appears in the August issue of the journal Expert Review of Neurotherapeutics.
A landmark 2006 study known as SPARCL, published in the New England Journal of Medicine, found that in patients who have experienced strokes or transient ischemic attacks (mini strokes), statins reduced the risk of subsequent strokes by 16 percent.
But this benefit generally applies only to patients who have experienced ischemic strokes, which are caused by blood clots in brain vessels. About 85 percent of strokes are ischemic.
And even among ischemic stroke patients, there is a small subgroup that should be placed on statin therapy only "with circumspection," the researchers write. These patients are those who have had strokes in small blood vessels, have poorly controlled high blood pressure and consume more than one drink of alcohol per day.
The picture is more varied for the 15 percent of stroke patients who have had hemorrhagic strokes (caused by bleeding on or in the brain). There are two types of hemorrhagic stroke: aneurysmal subarachnoid hemorrhage (SAH) and intracranial hemorrhage (ICH). An SAH stroke involves bleeding over the surface of the brain, while an ICH stroke involves bleeding inside the brain.
Statins have been postulated to help recovery in patients with SAH. While the jury is still out, "the overall evidence slightly favors a benefit," researchers wrote.
But high-dose statin therapy "should be avoided as routine therapy in ICH patients until the competing risks and benefits are better understood," the researchers wrote.
Complicating matters further, if a patient whom is on statins experiences an SAH or ICH stroke, he or she should remain on the drugs in the short run. "Reassessment of continuing statin utility in these patients should be considered immediately after recovery," researchers write.
Flaster and his colleagues wrote that more research is needed:
"Clearly, the potential influences of statins are so broad and mixed and the potential for effects and countereffects so likely that both careful science and detailed clinical investigation, especially well-designed clinical trials, will be needed to realize and document effective and safe therapeutic intervention."
Flaster is an associate professor in the departments of Neurology and Neurological Surgery at Loyola University Chicago Stritch School of Medicine. He also is medical director of Loyola's outpatient neurology clinic.