Background: Cardiovascular disease is the most common cause of death and disability in the Western world. Statins are known to reduce the risk of death and further disability in persons with established cardiovascular disease; however, the risk reduction for those with risk factors but without diagnosed cardiovascular disease has not been clear. Brugts and colleagues conducted a meta-analysis of randomized controlled trials (RCTs) that focused on primary prevention or included subgroups of patients without known cardiovascular disease to clarify the role of statins in reducing all-cause mortality and the incidence of significant cardiovascular and cerebrovascular events.
The Study: The authors selected RCTs of statins versus controls (i.e., placebo, active control, or usual care) in at-risk patients. Studies were included if they had at least one year of follow-up; used death or cardiovascular events as primary outcomes; and enrolled at least 80 percent of patients without diagnosed cardiovascular disease or reported data separately on a sole primary prevention group.
Results: Of the 1,230 studies reviewed, 10 met the inclusion criteria and included 70,388 participants; 35,138 were randomized to the statin group and 35,250 to the control group. The mean age of participants was 63 years; 34 percent were women and 23 percent had diabetes. During a mean follow-up of 4.1 years, 5.1 percent of participants in the statin group died, compared with 5.7 percent in the control group, for a 12 percent relative risk reduction in all-cause mortality. Similarly, statin use was associated with a 30 percent relative risk reduction in major cardiovascular events, and a 19 percent relative risk reduction in major cerebrovascular events compared with the control group. There was no significant difference in cancer rates between the statin and control groups. These results did not vary much among men and women, patients older than 65 years, those 65 years and younger, and those with diabetes.
Conclusion: In patients with cardiovascular risk factors but without established cardiovascular disease, long-term statin use reduces the risk of death and cardiovascular morbidity. The relative risk reduction for primary prevention is similar to that reported for secondary prevention.