Each study used a different drug from a group called HMG-CoA reductase inhibitors: simvastatin (Zocor) in the Scandinavian Simvastatin Survival Study (4S) and pravastatin in CARE. Researchers who designed 4S did not plan to test simvastatin's effectiveness in stroke, but in 1994 they reported a retrospective analysis that showed fewer strokes in patients getting simvastatin.
CARE, however, did include stroke reduction as a secondary part of its investigation. Plehn says that this part of the investigation makes the CARE stroke analysis more acceptable to statisticians. The team's initial paper in 1996 reported a 31 percent reduction in stroke, based on the reports of study investigators.
The new stroke analysis presented at the American Heart Association meeting involved a far-more detailed examination of the CARE data. The records of any patient who might have suffered a stroke were examined by two members of a special committee.
"Strokes are sometimes hard to diagnose," Plehn says. "We looked at hundreds of reported events to verify that they had indeed been strokes and not migraine headaches or something else that might appear to be strokes."
This work revealed that 128 CARE participants (52 taking pravastatin and 76 on placebo) suffered confirmed strokes during the median follow-up period of five years. The data showed a 32 percent lower risk for the drug group. A total of 216 people (92 on pravastatin and 124 on placebo) suffered either a stroke or TIA, a risk reduction of 27 percent for those getting pravastatin.
These findings held up when the team adjusted the results for age, sex,
history of hypertension, cigarette smoking, diabetes, and levels of t
Contact: Brian Henry
American Heart Association