Heart Protection Study

The "Heart Protection Study" was a large randomized controlled trialrun by the Clinical Trial Service Unit, and fundedby the Medical Research Council (MRC) and the British Heart Foundation (BHF) in the United Kingdom. It studied the use of statin (simvastatin 40 mg) medication and vitamin supplementation (vitamin E, vitamin C and beta carotene) in patients that are at risk for cardiovascular disease.

Results

An outline of the study protocol was published in 1999 ["MRC/BHF Heart Protection Study of cholesterol-lowering therapy and of antioxidant vitamin supplementation in a wide range of patients at increased risk of coronary heart disease death: early safety and efficacy experience." Eur Heart J 1999;20:725-41. [http://eurheartj.oxfordjournals.org/cgi/reprint/20/10/725 PDF] . PMID 10329064.] . Initial results [Heart Protection Study Collaborative Group. "MRC/BHF Heart Protection Study of cholesterol lowering with simvastatin in 20,536 high-risk individuals: a randomised placebo-controlled trial." Lancet 2002;360:7-22. PMID 12114036.] were published in 2002, which indicated that vitamins made little difference in modifying cardiovascular risk, but that simvastatin could significantly reduce the risk of cardiovascular events. Further results, from 2003 and 2004, focused on the role of simvastatin in diabetics [Collins R, Armitage J, Parish S, Sleigh P, Peto R; Heart Protection Study Collaborative Group. "MRC/BHF Heart Protection Study of cholesterol-lowering with simvastatin in 5963 people with diabetes: a randomised placebo-controlled trial." Lancet 2003;361:2005-16. PMID 12814710] and preventing stroke [Collins R, Armitage J, Parish S, Sleight P, Peto R; Heart Protection Study Collaborative Group. "Effects of cholesterol-lowering with simvastatin on stroke and other major vascular events in 20536 people with cerebrovascular disease or other high-risk conditions." Lancet 2004;363:757-67. PMID 15016485.] . A 2005 paper analyses the cost-effectiveness of a prescribing strategy similar to the one employed in the study [Mihaylova B, Briggs A, Armitage J, Parish S, Gray A, Collins R; Heart Protection Study Collaborative Group. "Cost-effectiveness of simvastatin in people at different levels of vascular disease risk: economic analysis of a randomised trial in 20,536 individuals." Lancet 2005;365:1779-85. PMID 15910950.] .

Interpretation

The HPS is to date the largest study to investigate the use of statins in the prevention of cardiovascular disease. While there have been concerns about side-effects (myopathy and rhabdomyolysis), these were rare in this study.

The number needed to treat in the study was 57 patients to postpone one death and 19 to prevent one cardiovascular "event" (in those taking the drug simvastatin/Zocor for 5 years). There was no mortality benefit in women. Cancer risk was suggestively lower in the treatment group (this has been the subject of other studies; for example, the PROSPER study found more cancer deaths and significantly more cancer incidence). No worsening of lung disease was found, an initial concern with statin drugs, and simvastatin did not decrease osteoporosis.

The CTSU branch of Oxford has been criticized for not releasing all group study data about deaths and for inappropriately combining dissimilar endpoints and groups to suggest benefit for all. Having received over £m105 ($m200) from cholesterol-lowering drug manufacturers in addition to the funding from the sources listed above, their objectivity has been questioned. For example here: http://blogs.wsj.com/health/2008/09/18/statistics-smackdown-experts-duel-over-vytorin-cancer-data/

References

See also

* [http://www.hpsinfo.org Study homepage] at the Clinical Trial Service Unit
* [http://www.jr2.ox.ac.uk/bandolier/booth/cardiac/HPS.html Bandolier condensation of the HPS results]