The cholesterol-fighting class of drugs known as statins are associated with a reduction in the risk of stroke by about one fifth compared with placebo, according to French researchers. The findings, which involved analyzing 24 studies involving more than 165,000 patients, are reported in the May edition of The Lancet Neurology.

 

Statins not only lower the overall risk of stroke but also slow the progression of blockage of the carotid arteries supplying the brain. They also reduce inflammation and endothelial dysfunction, decrease platelet aggregation, improve the breakdown of fibrin clots, lower blood pressure, and decrease the risk of thromboembolic complications to the brain by reducing the incidence of heart attacks. Statins might also have a neuroprotective effect.

 

Only one of the 24 studies assessed statin use for secondary prevention of stroke. It found that intense reduction of LDL cholesterol by statins also reduced the risk of recurrent stroke by 16 percent and of major cardiovascular events by 20 percent. The treatment effect did not differ in men versus women, in individuals aged less than 65 years versus those aged more than 65 years, in those with narrowing of the carotid arteries or no narrowing, in patients with diabetes versus without diabetes, and across stroke subtype at entry.

 

The authors also studied the effect of statins on hemorrhagic stroke (bleeding in the brain caused by rupture of a blood vessel)—representing 20 percent of all strokes. Two previous studies had suggested that statins might increase the risk of hemorrhage. However the analysis found no evidence that statin use increased the risk of hemorrhagic stroke, except in patients with prior brain bleeds.

 

Because of the increased incidence of hemorrhagic stroke seen in patients that had previously suffered from the condition, the researchers recommend caution when considering statin therapy in patients with prior history of cerebral hemorrhage. Pending further data from other secondary prevention trials in patients with stroke, they say they would only prescribe statins to patients who are at high risk of major coronary or other atherothrombotic events, and would not aim to aggressively reduce cholesterol concentrations.

 

The ratio of HDL (good) to LDL (bad) cholesterol is the best predictor of stroke and heart attacks (and better than LDL cholesterol alone). As a result, the researchers say the benefits and risks of raising HDL cholesterol concentrations with specific drugs such as niacin or the new cholesteryl ester transfer protein inhibitors are worth investigation to reduce the risk of other therapies.

 

The researchers say the next step in this field is to assess the safety and effectiveness of further reductions in LDL cholesterol after a stroke. Other approaches they say that might decrease the residual risk of stroke are triglyceride-lowering therapy with fibric acid compounds, or their combination with statins, and treatments to raise HDL cholesterol concentrations.