Physicians' Academy for Cardiovascular Education

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

Literature - Ford I et al., Circulation 2016

Long Term Safety and Efficacy of Lowering LDL Cholesterol With Statin Therapy: 20-Year Follow-Up of West of Scotland Coronary Prevention Study


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

1. Stone NJ, Robinson JG, Lichtenstein AH, et al. 2013 ACC/AHA guideline on the treatment of blood cholesterol to educe atherosclerotic cardiovascular risk in adults. Circulation. 2014;129(25 suppl 2):S1-S45.
2. Perk J, De Backer G, Gohlke H, et al. European guidelines on cardiovascular disease prevention in clinical practice (version 2012). The Fifth Joint Task Force of the European Society of Cardiology and Other Societies on Cardiovascular Disease Prevention in Clinical Practice (constituted by representatives of nine societies and by invited experts). Eur Heart J. 2012;33:1635-1701.
3. Redberg RF, Katz MH. Healthy men should not take statins. JAMA. 2012;307:1491-1492.
4. Taylor FC, Huffman M, Ebrahim S. Statin therapy for primary prevention of cardiovascular Disease. JAMA. 2013;310:2451-2452.
5. Yeboah J, Sillau S, Delaney JC, et al. Implications of the new American College of Cardiology/American Heart Association cholesterol guidelines for primary atherosclerotic cardiovascular disease event prevention in a multi ethnic cohort: Multi-Ethnic Study of Atherosclerosis (MESA). Am Heart J. 2015;169:387-395.
6. Ford I, Murray H, Packard CJ, et al. Long-Term Follow-up of the West of Scotland Coronary Prevention Study. N Engl J Med. 2007;357:1477-1486.
7. McConnachie A, Walker A, Robertson M, et al. Long-term impact on healthcare resource utilization of statin treatment, and its cost effectiveness in the primary prevention of cardiovascular disease: a record linkage study. Eur Heart J. 2014;35:290-298.