The Coronary Drug Project (CDP) was a large

clinical trial Clinical trials are prospective biomedical or behavioral research studies on human subject research, human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel v ...

which assessed several different treatments for

coronary heart disease Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves Ischemia, the reduction of blood flow to the myocardium, heart muscle due to build-up o ...

in men with previous

myocardial infarction A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which ...

. The study was conducted from 1965 to 1985 at 53 clinical centers and

randomized In common usage, randomness is the apparent or actual lack of pattern or predictability in events. A random sequence of events, symbols or steps often has no order and does not follow an intelligible pattern or combination. Individual rand ...

8,341 men age 30 to 64 years to six different treatment groups: low-dose

estrogen Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal a ...

therapy (2.5 mg/day

oral The word oral may refer to: Relating to the mouth * Relating to the mouth, the first portion of the alimentary canal that primarily receives food and liquid **Oral administration of medicines ** Oral examination (also known as an oral exam or ora ...

conjugated estrogens Conjugated estrogens (CEs), or conjugated equine estrogens (CEEs), sold under the brand name Premarin among others, is an estrogen medication which is used in menopausal hormone therapy and for various other indications. It is a mixture of th ...

), high-dose estrogen therapy (5 mg/day oral conjugated estrogens),

clofibrate Clofibrate (trade name Atromid-S) is a lipid-lowering agent used for controlling the high cholesterol and triacylglyceride level in the blood. It belongs to the class of fibrates. It increases lipoprotein lipase activity to promote the conversion ...

(1.8 g/day), dextrothyroxine (6 mg/day),

niacin Niacin, also known as nicotinic acid, is an organic compound and a form of vitamin B3, an essential human nutrient. It can be manufactured by plants and animals from the amino acid tryptophan. Niacin is obtained in the diet from a variet ...

(3 g/day), and

placebo A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like Saline (medicine), saline), sham surgery, and other procedures. In general ...

(

lactose Lactose is a disaccharide sugar synthesized by galactose and glucose subunits and has the molecular formula C12H22O11. Lactose makes up around 2–8% of milk (by mass). The name comes from ' (gen. '), the Latin word for milk, plus the suffix ...

3.8 mg/day). The high-dose estrogen group was discontinued in 1970 due to increased non-fatal

cardiovascular complication Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, ...

s and an unfavorable trend in overall mortality, while the low-dose estrogen group was discontinued in 1970 due to lack of indication of benefit and also an unfavorable trend in overall mortality. Both dose levels of estrogen as well as clofibrate were also found to increase the incidence of

gallbladder disease Gallbladder diseases are diseases involving the gallbladder and is closely linked to biliary disease, with the most common cause being gallstones (cholelithiasis). The gallbladder is designed to aid in the digestion of fats by concentrating and ...

in the study. The dextrothyroxine group was discontinued in late 1971 due to increased cardiovascular mortality. The Coronary Drug Project Aspirin Study was a substudy of the CDP which randomized men from the estrogen and dextrothyroxine groups of the trial which had been terminated early to either

aspirin Aspirin, also known as acetylsalicylic acid (ASA), is a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and/or inflammation, and as an antithrombotic. Specific inflammatory conditions which aspirin is used to treat in ...

or placebo.

References

{{Reflist Clinical trials Evidence-based medicine Ischemic heart diseases