Heart Protection Study
Encyclopedia
The Heart Protection Study was a large randomized controlled trial
run by the Clinical Trial Service Unit
, and funded
by 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 who are at risk of cardiovascular disease
.
s 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 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.
Randomized controlled trial
A randomized controlled trial is a type of scientific experiment - a form of clinical trial - most commonly used in testing the safety and efficacy or effectiveness of healthcare services or health technologies A randomized controlled trial (RCT) is a type of scientific experiment - a form of...
run by the Clinical Trial Service Unit
Clinical Trial Service Unit
The Clinical Trial Services Unit is a medical research institute within Oxford University in the United Kingdom.It primarily conducts large scale clinical trials and epidemiological studies of chronic diseases, especially cancer and vascular conditions.It is located in the Richard Doll Building ...
, and funded
by the Medical Research Council
Medical Research Council (UK)
The Medical Research Council is a publicly-funded agency responsible for co-ordinating and funding medical research in the United Kingdom. It is one of seven Research Councils in the UK and is answerable to, although politically independent from, the Department for Business, Innovation and Skills...
(MRC) and the British Heart Foundation
British Heart Foundation
The British Heart Foundation is a charity organisation in Britain that funds research, education, care and awareness campaigns aimed to prevent heart diseases in humans.-Foundation:...
(BHF) in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
. It studied the use of statin
Statin
Statins are a class of drugs used to lower cholesterol levels by inhibiting the enzyme HMG-CoA reductase, which plays a central role in the production of cholesterol in the liver. Increased cholesterol levels have been associated with cardiovascular diseases, and statins are therefore used in the...
(simvastatin
Simvastatin
Simvastatin is a hypolipidemic drug used to control elevated cholesterol, or hypercholesterolemia. Simvastatin is a member of the statin class of pharmaceuticals, is a synthetic derivate of a fermentation product of Aspergillus terreus.-Medical uses:The primary uses of simvastatin is for the...
40 mg) medication
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
and vitamin
Vitamin
A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. In other words, an organic chemical compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on...
supplementation (vitamin E
Vitamin E
Vitamin E is used to refer to a group of fat-soluble compounds that include both tocopherols and tocotrienols. There are many different forms of vitamin E, of which γ-tocopherol is the most common in the North American diet. γ-Tocopherol can be found in corn oil, soybean oil, margarine and dressings...
, vitamin C
Vitamin C
Vitamin C or L-ascorbic acid or L-ascorbate is an essential nutrient for humans and certain other animal species. In living organisms ascorbate acts as an antioxidant by protecting the body against oxidative stress...
and beta carotene
Carotene
The term carotene is used for several related unsaturated hydrocarbon substances having the formula C40Hx, which are synthesized by plants but cannot be made by animals. Carotene is an orange photosynthetic pigment important for photosynthesis. Carotenes are all coloured to the human eye...
) in patients who are at risk of cardiovascular disease
Cardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
.
Results
An outline of the study protocol was published in 1999. Initial results 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 and preventing stroke. A 2005 paper analyses the cost-effectiveness of a prescribing strategy similar to the one employed in the study.Interpretation
The HPS is to date the largest study to investigate the use of statinStatin
Statins are a class of drugs used to lower cholesterol levels by inhibiting the enzyme HMG-CoA reductase, which plays a central role in the production of cholesterol in the liver. Increased cholesterol levels have been associated with cardiovascular diseases, and statins are therefore used in the...
s in the prevention of cardiovascular disease
Cardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
. While there have been concerns about side-effects (myopathy
Myopathy
In medicine, a myopathy is a muscular disease in which the muscle fibers do not function for any one of many reasons, resulting in muscular weakness. "Myopathy" simply means muscle disease...
and rhabdomyolysis
Rhabdomyolysis
Rhabdomyolysis is a condition in which damaged skeletal muscle tissue breaks down rapidly. Breakdown products of damaged muscle cells are released into the bloodstream; some of these, such as the protein myoglobin, are harmful to the kidneys and may lead to kidney failure...
), these were rare in this study.
The number needed to treat
Number needed to treat
The number needed to treat is an epidemiological measure used in assessing the effectiveness of a health-care intervention, typically a treatment with medication. The NNT is the average number of patients who need to be treated to prevent one additional bad outcome...
in the study was 57 patients to postpone one death and 19 to prevent one cardiovascular "event" (in those taking the drug simvastatin for 5 years). There was no mortality benefit in women. Cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
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
Osteoporosis
Osteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered...
.
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.
See also
- Study homepage at the Clinical Trial Service UnitClinical Trial Service UnitThe Clinical Trial Services Unit is a medical research institute within Oxford University in the United Kingdom.It primarily conducts large scale clinical trials and epidemiological studies of chronic diseases, especially cancer and vascular conditions.It is located in the Richard Doll Building ...
- Bandolier condensation of the HPS results