Statins for millions more?

Abstract

Last week, the National Institute for Health and Care Excellence (NICE) in the UK unveiled draft guidance on cardiovascular risk assessment and, in particular, on lipid modification for the primary and secondary prevention of cardiovascular disease. In an update to the existing guideline, the new proposal is that the threshold be halved for prescribing statins to prevent cardiovascular disease, which includes coronary heart disease and stroke. Current advice is to prescribe statins to people with at least a 20% risk of developing cardiovascular disease in the next 10 years. The new guidance, issued for public consultation, and based on a cost-effectiveness analysis, recommends offering statins to those with a 10% or greater 10 year risk of developing cardiovascular disease. Now that most statins are cheap, and more benefits of statins have been demonstrated, treatment has become cost effective for lower absolute risks than previously. NICE recommends the QRISK2 tool to calculate the percentage risk of developing cardiovascular disease. QRISK2 takes into account factors such as age, smoking history, cholesterol, blood pressure, atrial fibrillation, and body-mass index, as well as a family history of heart disease. Atorvastatin 20 mg daily is recommended for the primary prevention of cardiovascular disease, whereas patients with established cardiovascular disease, type 1 diabetes, or type 2 diabetes should in general be offered atorvastatin 80 mg daily. NICE emphasises the need for lifestyle changes, especially stopping smoking, eating healthily, losing excess weight, drinking less alcohol, and doing more exercise. Intended for use in the NHS in England, Wales, and Northern Ireland, registered stakeholders are invited to comment on the provisional recommendations. The consultation process is open until March 26, and the final NICE guideline is due to be published in July, 2014. Although death rates from cardiovascular disease have halved since the 1970s and 1980s, it remains the leading cause of death in England and Wales, killing one in three people in 2010. About two thirds of these deaths were due to coronary heart disease, and a third due to stroke. Fewer die, but the morbidity and long-term ill health caused by cardiovascular disease are increasing, especially in association with social deprivation. Critics of these new recommendations have been quick to point out the risks of mass medicalisation, citing common side-effects of statins, and calling for lifestyle modification as the preferred, relatively risk-free, solution. 7 million people already take statins in the UK; millions more are likely to if the new NICE guidance is implemented. Publication of the NICE proposals follows new guidelines from the American Heart Association (AHA) and the American College of Cardiology (ACC), released in November, 2013, which also recommend more aggressive use of statins. For primary prevention, these US guidelines recommend statins for those with at least a 7·5% 10 year risk of cardiovascular disease, and consideration of statins for those with 10 year risks of between 5% and 7·5%. The AHA/ACC guidelines use a newly developed risk prediction algorithm, which has led to widespread debate, including contributions from Paul Ridker and Nancy Cook in these pages, who stated that risk might be overestimated by as much as two fold. Last week in our Correspondence section the discussion continued with David van Klaveren and colleagues recommending “building guidelines on adequate estimates of absolute treatment benefit, requiring a recalibrated absolute risk prediction model in conjunction with individualised estimates of the relative risk reduction”. As Paul Ridker and Nancy Cook said, “No trial of statin therapy has ever used a global risk prediction score as an enrolment criterion, so basing prescription on such a metric might be difficult to defend in an evidence-based climate.” In John Ioannidis' view published in JAMA on Feb 5, “The ACC/AHA guidelines demonstrate that even in a topic area with extensive amounts of data and published clinical trials, crucial evidence is still missing.” He called for trials to demonstrate the best predictive model and treatment threshold. So how should doctors and patients decide whether to start a statin? Experts, it seems, disagree. Reliance on risk prediction tools to calculate cardiovascular risk is problematic. At a minimum, frequent calibration of risk tools, in contemporary cohorts, is essential, as is prospective long-term confirmation of risk prediction. It might be wise to remember the disclaimer on QRISK2's website: “The authors and the sponsors accept no responsibility for clinical use or misuse of these score[s]”. In the end, it is the doctor and patient in the consulting room who must decide when lifestyle measures are not enough.