Extended follow-up of the WOSCOPS trial supports statin use for primary CV prevention

Ford I, Murray H, McCowan C, et al.
Circulation 2016;published online ahead of print

Background

Control of LDL-c levels is a cornerstone in the prevention of cardiovascular (CV) disease [1,2]. However, open questions remain regarding the selection of individuals, the target LDL levels, and the overall risk/benefit-ratio of this strategy in the primary prevention setting [3-5], given that the long-term use of statins has been associated with adverse events, such as cancer [6].
Long-term follow-up studies, such as the West of Scotland Coronary Prevention Study (WOSCOPS), enhance the understanding of the consequences of this intervention [6]. In the WOSCOPS trial, pravastatin treatment during a 15-year follow-up period was associated with further reduction in coronary events without particular safety concerns, and with a favourable cost-saving profile [7].
This analysis evaluates the 20-year impact of 4.9 years of pravastatin therapy vs. placebo on mortality and cumulative morbidity in a high-risk cohort of men with elevated LDL-c levels but without a history of myocardial infarction. Statin use was recorded only for 5 years after the completion of the original trial, and it is not known which lipid-lowering therapy has been used during the last 10 years of follow-up.

Main results

• Mortality: as compared with placebo, in the pravastatin arm reductions were seen in:

• all-cause mortality: HR: 0.87; CI 95%: 0.80-0.94; P = 0.0007
• CV death: HR: 0.79; CI 95%: 0.69-0.90; P = 0.0004
• coronary mortality: HR: 0.73; CI 95%: 0.62 – 0.86; P = 0.0002

• Cumulative CV hospitalisation: the pravastatin treatment arm showed lower event rates:

• by 18% for any coronary event (P = 0.002)
• by 24% for myocardial infarction (P = 0.01)
• by 35% for heart failure (P = 0.002)

• Hospital admissions associated with complications of diabetes: the pravastatin arm showed: 

• fewer diabetes-related non-CV hospital admissions: HR: 0.81; CI 95%: 0.67 – 0.98; P = 0.030
• fewer hospital admissions involving complications of diabetes: HR: 0.33; CI 95%: 0.16 – 0.66; P = 0.0016

• Non-CV outcomes:

• there were no difference in non-CV or cancer death rates between groups
• there were no significant differences between groups in hospitalisation for non-CV causes

Conclusion

In a high-risk cohort of men with elevated LDL-c levels but without a history of myocardial infarction, statin treatment for 5 years was associated with reduced mortality and cumulative morbidity after 20 years. These results support the hypothesis that statin use for the primary prevention of cardiovascular disease contribute to a sustained long-term clinical benefit in clinical practice.

Find this article online at Circulation

References

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