Does intensive cholesterol-lowering therapy affect the risk of hemorrhagic stroke?

This study investigated the effect of low-density lipoprotein cholesterol (LDL-C) levels on hemorrhagic stroke risk. Researchers suggested that the use of intensive cholesterol-lowering therapy is not associated with an increased risk of hemorrhagic stroke.

A stroke might happen due to a blood clot (ischemic) or a burst blood vessel (hemorrhagic). There is a blockage of the blood flow to the brain and thus of a lack of oxygen. Without oxygen, brain cells begin to die which results in symptoms such as paralysis. An ischemic stroke can happen if cholesterol builds up on blood vessels. This helps a small blood clot block the blood vessel. In order to prevent an ischemic stroke, patients commonly receive cholesterol-lowering medications.

Hemorrhagic strokes include 10 to 20% of all strokes and are associated with high mortality rates. A few studies have found that very low levels of LDL-cholesterol ("bad" cholesterol) might increase the risk of hemorrhagic stroke. Prior studies did not find an association between hemorrhagic stroke risk and LDL-C levels below 70 mg/dL. However, the effect of LDL-C as low as below 55 mg/dl, as is recommended by the treatment guidelines, is still unknown.

This study reviewed 8 other studies with information about 122.802 patients. Of these, 62.526 patients were treated with intensive cholesterol-lowering therapies to achieve LDL-cholesterol levels below 55 mg/dl. 60.276 patients received a control therapy.

No difference was seen in the occurrence of hemorrhagic stroke between the group who received more intensive LDL-cholesterol lowering therapy (levels under 55 mg/dL) and less intensive treatment. 

This study concluded that an LDL-cholesterol level of under 55 mg/dl is not associated with an increased risk of hemorrhagic stroke.

This study analyzed very different trials, with different protocols. Cholesterol-lowering medications used were different. The follow-up period was also different among trials. This might have influenced the results.