As the UK descends into hysteria around petrol and pasties, I have been reflecting for the last week on Peter Rothwell’s recent Lancet papers about cancer prevention and the role of aspirin. Basically, daily low-dose aspirin not only prevents development of new cancer, but also the spread of cancer. Aspirin is one of the oldest drugs in the drug cabinet of hospital wards and GP surgeries, but we continue to discover more about its roles in medicine. As new evidence appears on the horizon, the information and guidelines for practising doctors and their patients still continues to change. There are inevitably time delays in how quickly new information filters through healthcare settings and broader society, and how it is interpreted by both the patient and the doctor.

Aspirin has several different uses which are proven by large bodies of evidence, including as a painkiller, prevention of cardiovascular disease in people at risk (primary prevention) and people with known cardiovascular disease (secondary prevention) and now for prevention of cancer. I always love to refer back to the Hippocratic Oath, and so we have to weigh aspirin’s harms with these many benefits. The main harm with aspirin is bleeding, particularly people who have a tendency towards bleeding anyway, e.g. individuals with history of gastric ulcers.

Interestingly, as the new data is emerging about the long-term preventive effects on cancer, the use of aspirin for two other indications is in decline due to evidence of not that much good when weighed against the risk of bleeding. First, most doctors do not recommend low-dose aspirin for primary prevention of cardiovascular disease, largely due to available data from meta-analyses showing that it does not change mortality in diabetics or non-diabetics. Second, in patients with atrial fibrillation, a heart rhythm problem which increases risk of stroke, aspirin is no longer recommended, yet most guidelinesaround the world still include it. So while we can recommend aspirin for long-term cancer prevention, we may not be able to recommend it in healthy individuals for long-term stroke prevention.

Evidence-based medicine is following a moving target of diseases and treatments and so the evidence is also always changing, even for drugs as old as aspirin. So for newer drugs, you can begin to imagine how little we know. The challenge is to keep all people, both doctors and patients up-to-date with all available evidence and guidelines. However, we know that this is difficult, given that both doctors do not always follow guidelines and people do not generally like to take tablets. Notably, most news reports covering the “aspirin and cancer” story advised people to go and see their doctor before starting the drug. Fergus Walsh, of the BBC, quoted a notable academic, “Doctors were good at treating disease, but when it came to preventing ill-health then people had to make their own judgements”. I agree. I wonder whether people have as much chance of making the “right decision” themselves. And before you ask, I do not take an aspirin a day yet, but I did start cycling to work again this week. One preventive step at a time.

The debate on the best way forward for primary prevention continues, and today cebmblog published:

Heneghan C. Considerable uncertainty remains in the evidence for primary prevention of cardiovascular disease [editorial]. The Cochrane Library 2011 19 Jan.

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality worldwide, and therefore strategies that aim to improve prevention in people without existing disease (primary prevention) are important for managing the overall burden of disease. This edition of The Cochrane Library adds to the evidence-base in this area with publication of two Cochrane Reviews on such preventive strategies: multiple risk factor interventions for primary prevention of coronary heart disease, and statins for the primary prevention of CVD. read more

One of my major issues with primary prevention is:
'Given the current limitations of the evidence-base, the alternative approach for policy is to focus on population-wide prevention. Widely publicised by Geoffrey Rose,legislating for smoke-free public spaces, re-designing public spaces to improve exercise or reducing daily dietary salt intake prove generally effective and can be cost-saving interventions.'

If you haven't already read a copy of Rose's book, you should,
get yourself a copy now. It should be compulsary reading for commissioners, docs and anyone involved in health prevention.

Coronary heart disease (CHD), which usually presents as a heart attack (or myocardial infarction, MI) is the most common cause of death and disability both in the UK and globally. The way in which CHD is treated and prevented therefore has huge implications for patients, health professionals and policymakers. Once a person has a heart attack, prevention of further heart attacks, stroke or death, or secondary prevention, is crucial. There is strong evidence for benefit of several drugs and treatments after heart attacks to this end, including aspirin, statins, ACE inhibitors and beta-blockers. Such treatments have undoubtedly saved lives, but studies in the US and the UK, have shown that between 30-60% of MI patients receive appropriate treatment. There are strong arguments for giving more people the right drugs with benefits in terms of mortality and cost-effectiveness. Current NICE guidelines therefore recommend these treatments for all patients following a heart attack.

This week, the British Heart Foundation reported that only 38% of such patients were receiving adequate rehabilitation care. “Cardiac rehab includes advice from dieticians, physiotherapists and psychologists about how to live with the consequences and improve the survival chances following heart attacks, coronary artery bypass operations and angioplasties.” The components of cardiac rehab have benefits individually and together. For example, a review of 46 trials including 9000 patients showed that exercise-based rehabilitation reduces all deaths by 20%, and cardiac deaths by 26%. Some patients are too ill to benefit from cardiac rehabilitation, and others choose not to partake or continue with the rehabilitation programme.

Provision of drug treatment and primary angioplasty programmes has improved more than cardiac rehabilitation, which has remained the poor relation. This is partly because we tend to favour treatment rather than prevention, and pills rather than behaviour changes. To a greater extent than other treatments, cardiac rehabilitation needs the commitment of the patient. However, this does not mean that we cannot be innovative in designing ways of increasing access to this vital aspect of care for patients after MI.