National Institute for Health and Care Excellence (NICE) issued new draft guidance on the use of statins for primary prevention of cardiovascular events, recommending that they should now be considered for people at a lower risk threshold than before.
"If more people took statins, there would be a greater reduction in the incidence of heart disease and strokes," the committee said.
Previously NICE recommended that people with a risk of a cardiovascular event of 10% or higher over 10 years should be offered a statin. The new guidance partly updated the clinical guideline on cardiovascular disease (CVD) risk assessment and reduction originally published in 2014 and last updated in 2016. It follows consideration by the NICE committee of new evidence on the side effects and safety of statins.
Decision Should be Left to Individual Patients
Paul Chrisp, director of the Centre for Guidelines at NICE, said: "What we’re saying is that, for people with a less than 10% risk over 10 years of a first heart attack or stroke, the decision to take a statin should be left to individual patients after an informed discussion of benefits and risks.
"The evidence is clear, in our view, that for people with a risk of 10% or less over 10 years, statins are an appropriate choice to reduce that risk. We are not advocating that statins are used alone. The draft guideline continues to say that it is only if lifestyle changes on their own are not sufficient, and that other risk factors such as hypertension are also managed, that people who are still at risk can be offered the opportunity to use a statin, if they want to. They don’t have to, and their decision should be informed by an understanding of the risks and tailored to their values and priorities."
NICE estimated that the risk reduction attributable to statin treatment amounted to about 20 people per thousand (2%) with a 10-year risk of 5% who would not get heart disease or have a stroke because of the treatment. This figure doubled for the current threshold of 10% 10-year risk of 40 per thousand (4%). NICE further estimated that for individuals with an average 10-year risk of 20%, around 70 people per thousand (7%) would not get heart disease or have a stroke in the next 10 years.
Risk Scores Do Not Replace Clinical Judgement
The committee assessed 16 cohort studies published in 17 papers on the validation of 11 risk assessment tools for CVD events and mortality (in particular cardiovascular mortality, non-fatal myocardial infarction and stroke). It said that while all of the tools had limitations, they could be useful in distinguishing low, medium and high-risk groups. However "using an appropriate risk assessment tool should not replace clinical judgement", and "risk score interpretation should be individualised".
NICE assessed adverse effects from statins detailed in 24 previously included studies that were retained in the analysis and in seven randomised trials reported in 10 papers that were added to the review, along with two published systematic reviews.
Side-effects assessed included:
- Rhabdomyolysis (creatine kinase (CK)>10 times normal)
- Liver adverse events (transaminases>3 times normal level)
- New onset diabetes
- Worsening of diabetes:
- Diabetes adverse event of ketosis or glucose control complications
- Rise in HbA1c of ≥0.5% from baseline
- Escalation of diabetes medication
- Cognitive decline (by validated questionnaire) or dementia
- Haemorrhagic stroke
The overall finding was for "a small relative and absolute increase in cases of any muscle pain for people taking statins compared with placebo". However the committee noted that the effect was largely driven by the increased risk with high-intensity statins, with approximately 16% of users reporting muscle pain. "This was not thought to represent a clinically important harm of statins and was outweighed by the benefit seen for CVD event reduction," it said. In addition, none of the trials of high-intensity statins used atorvastatin 20 mg, which is the currently recommended first line agent for primary prevention.
Atorvastatin 20 mg Could be Considered for Primary Prevention
The new draft guideline therefore recommended that doctors consider prescribing atorvastatin 20 mg for the primary prevention of CVD for people with a 10-year risk of less than 10%, "where the person is happy to take a statin or there is concern that the person’s risk of a cardiovascular event may be underestimated". The current annual cost of this was estimated as £12 per patient.
NICE uses 'consider' recommendations when there is a closer balance between benefits and harms of an intervention that could be used. However it said that it had considered new evidence on the side effects and safety of statins, and concluded that more people could be given them. Although statins can sometimes cause side effects such as muscle pains, "the best evidence shows that most people don’t get muscle pains with statins", the rationing body said, "and many more people will get muscle pains whether they take statins or not than have muscle pain caused by statins".
Full guidance is expected to be published on 17 May 2023