May 17th, 2012
Large Meta-Analysis Finds Statins Effective in Low-Risk Patients
A very large meta-analysis provides strong evidence that the relative reduction in vascular risk with statins is at least as great in low-risk patients as in high-risk patients. The finding, write the authors, provides evidence that expansion of guidelines to lower-risk populations should be considered.
In their paper in the Lancet, the Cholesterol Treatment Trialists’ (CTT) Collaborators analyzed data from 134,537 patients in trials comparing statins with control therapy and 39,612 patients in trials comparing low- and high-dose statins. They examined the impact of statin therapy according to the baseline 5-year risk for a major vascular event on control therapy. Statin therapy caused a consistent reduction in the relative risk for major vascular events and all-cause mortality independent of other factors, including age, sex, baseline LDL cholesterol, or established CV disease.
Here are the rate ratios for major vascular events across five levels of risk at baseline (note that 1 mmol of LDL cholesterol is equivalent to about 39 mg/dL of LDL):
5-Year Risk Rate ratio per 1.0 mmol/L of LDL reduction
- <5% 0·62 [99% CI 0·47–0·81]
- ≥5% to <10% 0·69 [99% CI 0·60–0·79]
- ≥10% to <20% 0·79 [99% CI 0·74–0·85]
- ≥20% to <30% 0·81 [99% CI 0·77–0·86]
- ≥30% 0·79 [99% CI 0·74–0·84]
The meta-analysis found no evidence for harm associated with statin therapy, including cancer or other nonvascular mortality.
The authors note that current guidelines do not recommend statin therapy for people in the lowest two risk categories in the study, who are expected to have a 5-year event rate lower than 10%. As generic statins are highly cost-effective, they write, the study “suggests that these guidelines might need to be reconsidered.”
In an accompanying comment, Shah Ebrahim and Juan Casas ask whether everyone over the age of 50 should take statins. They calculate that, in the U.K., adoption of a threshold of 10% would classify 83% of men over age 50 and 56% of women over age 60 as needing statins.