The use of cholesterol-lowering "statin" drugs, such as Lipitor (atorvastatin)
and Zocor (simvastatin), may raise the risk of brain hemorrhage in patients who have experienced a recent stroke or a transient ischemic attack (TIA), new research suggests.

Still, this risk may be outweighed by the ability of these agents to lower the overall risk of a second stroke and other serious events, such as heart attack.

"This is a secondary analysis of data collected as part of the Stroke Prevention with Aggressive Reductions in Cholesterol Levels [SPARCL] study," lead author Dr. Larry B. Goldstein told Reuters Health.

The main finding of SPARCL, he said, was that atorvastatin reduced the risk of stroke by 16 percent in patients who recently had a stroke or TIA, a condition in which blood flow to a portion of the brain is temporarily reduced.

However, in an unplanned analysis, atorvastatin seemed to slightly increase the risk of brain hemorrhage.

In the present study, reported in the journal Neurology, Goldstein, from Duke University Medical Center in Durham, N.C., and colleagues explored this association further by analyzing data from 4,731 SPARCL participants. Sixty-seven percent of subjects had a prior low-blood-flow or "ischemic" stroke, 31 percent had a TIA, and 2 percent had a stroke caused by a brain hemorrhage.

Treatment with atorvastatin increased the risk of brain hemorrhage by 68 percent, the report indicates.

A prior hemorrhagic stroke raised the risk of brain hemorrhage by more than fivefold. Other factors that increased the risk included male gender, which raised the risk by 79 percent, and age, which elevated the risk by 42 percent for every 10 years of age. Further analysis showed that having high blood pressure — 160/100 mm Hg or higher — at the last study visit increased the odds of brain hemorrhage by more than sixfold.

Goldstein noted that data from observational studies have suggested that low cholesterol levels raise the risk of brain hemorrhage. "Since statins lower cholesterol, it was reasonable to think that the risk of brain hemorrhage was due to cholesterol lowering. However, we found no relationship between the level of cholesterol lowering and this risk."

According to Goldstein, the main message from SPARCL is that treatment with atorvastatin can reduce the risk of stroke in patients with a recent ischemic stroke or TIA, and the risk of brain hemorrhage is small.

However, for patients who have already had a hemorrhagic stroke, which constituted 2 percent of the study group, atorvastatin therapy did not seem to be beneficial.