Meta analysis casts doubt on the value of statins

[jimwalsh]

The value of statins in primary prevention has been thrown into doubt by a major meta-analysis which found no evidence the drugs reduce the risk of death in people at high risk of cardiovascular disease.

The evidence casts doubt on the usefulness of Health Check - the vascular screening programme - which is being rolled out to all people aged between 40 and 74 across England and Wales.
Claims by the previous Government that the programme would have a major impact on the number of myocardial infarcts and strokes appear to be undermined by new research, published in the Archives of Internal Medicine.
Researchers analysed data on all-cause mortality from 11 prospective randomised controlled trials of statin therapy between 1970 and 2009 performed in individuals free from cardiovascular disease at baseline.
The data from over 65,000 patients showed the use of statin ‘was not associated with a statistically significant reduction in the risk of all-cause mortality’, and reduced the risk of death by 9% compared to patients on a placebo control.
Similarly, there was no clear relationship between mean LDL-cholesterol and reduction in all-cause mortality, whether assessed in relation to absolute or percentage reduction.
Study leader Dr Kausik Ray, senior clinical research associate at the University of Cambridge and consultant cardiologist at Addenbrooke’s Hospital, said the findings suggest all-cause mortality benefits of statins are lower than thought - even among a high-risk primary prevention population.

He said: ‘Given the uncertainty about the mortality benefits and potential harm of lowering lipid levels in populations without clinically manifest CVD, our findings ... reinforce the notion that lowering lipid levels in a very high-risk primary prevention population is not likely to be harmful, but any mortality benefits are likely to be more modest than previously perceived.’
‘But it may be inferred that in even more lower-risk populations the benefits of mortality reduction are likely to be even more modest than observed here’
Professor Mike Kirby, Hertfordshire GP and professor of health and human sciences at the University of Hertfordshire, said: ‘These findings are a bit surprising though it’s worth bearing in mind that - when you’re looking at risk - high cholesterol is just one of the risks and these patients will really need a multifactorial approach.
‘But if statins are really not that useful in patients at high risk of cardiovascular disease then that may well feed into any review of the vascular screening programme.’
In an accompanying editorial in the Annals of Internal Medicine Dr Lee Green, a US GP described the study as ‘most complete meta-analysis of pharmacological lipid lowering for primary prevention.’
‘The meta-analysis makes it clear that in the short term, for true primary prevention, the benefit, if any, is very small. In the long term, although sincere advocates on both sides will try to convince us otherwise, we really must admit that we do not know.’
Archives of Internal Medicine 2010;170(12):1021-1031

http://www.pulsetoday.co.uk/story.asp?sectioncode=35&storycode=4126462&c=2


http://archinte.ama-assn.org/cgi/content/full/170/12/1024

one might make the point that the study looked at all cause mortality rather than CVS endpoints....

[Pebble]

Meta-analysis = spawn of the devil.

This is at least the fifth such met-analysis each one taking a slightly different tack each attacking the others methodology.

The fundamental problem is that these are 4 year trials, designed to test the impact of lipid lowering on cardiovascular events - since we know that changing lipid levels impacts cardiovascular events in that timeframe. There is scant evidence to suggest that in such a short time frame this converts to mortality benefit. Unfortunately from secondary prevention trials we know that where the cardiovascular event rate is high this does impact mortality so it is assumed that a similar approach can be applied to primary prevention. Those who pay for primary prevention want proof that it saves lives not just reduces morbidity, hence this kind of data trawling is encouraged, with over-reaction to any positive or negative meta-analysis, depending only on which side of the fence you sit.

[jimwalsh]

when we were taught about evidence and research meta-analysis/systematic review was put at the top of the pile. reading around it does seem open to personal bias creeping into the choice of papers and methodology...