The original West of Scotland Coronary Prevention Study (WOSCOPS) was a randomised placebo-controlled primary prevention trial which found that five years of treatment with pravastatin reduced the primary outcome of death from coronary heart disease (CHD) or nonfatal myocardial infarction (7.9% on placebo to 5.5% on pravastatin, P < 0.001) in middle aged Scottish men with hypercholesterolaemia and no evidence of previous myocardial infarction. A further 10 year extension study found a continued reduction in coronary events with no emerging safety issues. Overall, over 15 years, there was a reduction in all-cause mortality [hazard ratio, HR = 0.88, 95% CI (0.79–0.99), P = 0.03] and in coronary heart disease death or hospitalization [HR = 0.75, 95% CI (0.68–0.83), P < 0.001].
This extended analysis of the WOSCOPS long-term follow-up aimed to address recent concerns about the cost effectiveness of statins for primary prevention including the use of statins in healthy men.
The researchers assessed the impact on healthcare resource utilization, costs, and quality of life over 15 years from 5 years of statin use in WOSCOPS by linking during and post trial data to routinely collected health records.
The researchers estimated that five years treatment of 1,000 patients with pravastatin (40 mg/day) saved the NHS £710,000 (P < 0.001), including the cost of pravastatin and lipid and safety monitoring, and gained 136 QALYs (P = 0.017) over the 15-year period. These benefits (per 1000 subjects), attributable to prevention of cardiovascular events, included 163 fewer admissions and a saving of 1836 days in hospital, with fewer admissions for myocardial infarction, stroke, heart failure and coronary revascularization.
Furthermore there was no excess in non-cardiovascular admissions or costs (or in admissions associated with diabetes or its complications) and no evidence of heterogeneity of effect over sub-groups defined by baseline cardiovascular risk.
The researchers note that pravastatin is less potent than atorvastatin or rosuvastatin, therefore, theoretically these statins would confer greater benefits in reducing the cardiovascular risk, although with an increase in safety issues.
They suggest that based on these results treatment of even lower-risk individuals would still be economically efficient and deliver significant public health benefits. However, there remains uncertainty in relation to the potential for increased risk of diabetes with treatment of more than 5 years duration.
NICE is currently in the process of updating its guidance on lipid modification (CG 67) and statins for the prevention of cardiovascular events (TA 94) with final publication of the updated guidance in July 2014.