Glossary
Angina
Chest pain (squeezing, pressure, heaviness, tightening, or aching across the chest) due to an insufficient supply of oxygen-rich blood to the heart muscle. In most cases, the lack of blood supply to the heart is due to a narrowing of the coronary arteries as a result of coronary heart disease.
Angioplasty and stents
Coronary angioplasty is a procedure where a narrowed section of a coronary artery is widened by using a balloon and a stent attached to a catheter (a thin, flexible tube inserted into a coronary artery). The balloon at the tip of the catheter is blown up at the narrowed section of artery to force it wider. A 'stent' (small tubes made of metal mesh) is left in place to hold the artery open.
Arteries
One of the two types of blood supply pipes through which blood flows around the body. Arteries are the ones through which blood carrying oxygen, picked up in the lungs, supplies oxygen to the muscles and other tissues throughout the body. (Veins bring the blood back to the heart and to the lungs, where some of the body's waste products, such as carbon dioxide, are expelled as we breathe out).
Aspirin
Aspirin is a medicine which is usually used to relieve mild to moderate pain; reduce fever, redness, and swelling (doses of at least 300mg are used for pain relief). Aspirin is also used to reduce the risk of a second heart attack or stroke because it has blood thinning properties (i.e. it reduces the ability of blood to clot). Low doses of aspirin (75 to 150mg daily) are sufficient to have a blood thinning effect.
Beta-blockers
Beta-blockers work on the heart and blood vessels to reduce blood pressure and the amount of work the heart does. Atenolol (Tenormin) and propranolol (Inderal) are common examples. They are often used for treating high blood pressure, angina, heart attacks, heart rhythm disorders, and heart failure.
Cardiovascular disease
A term used to mean the 'furring up' or narrowing of arteries anywhere in the body: in the heart (coronary heart disease), in the brain (cerebrovascular disease) or in the main arteries or legs (peripheral vascular disease).
Carotid Endarterectomy
Carotid endarterectomy is an operation to treat carotid artery diseases. During the operation, the vascular surgeon removes the inner lining of the carotid artery (located on each side of the neck, supplying blood to the brain) if it has become thickened or damaged. This operation eliminates a substance called plaque (atherosclerotic changes built up by cholesterol, calcium, and fibrous tissue) from your artery and can restore blood flow to the brain.
Cerebrovascular disease
Term used to describe the 'furring up' or narrowing of the arteries leading to or in the brain. A sudden blockage of these arteries causes a stroke.
Cholesterol
Cholesterol is a type of fat (lipid) made by the body. It is essential for good health and is found in every cell in the body. There are two main types of cholesterol in the body: LDL-cholesterol (or 'bad' cholesterol) and HDL-cholesterol (or 'good' cholesterol). Having a high LDL-cholesterol level in the blood increases the risk of heart disease and stroke. We know that reducing LDL-cholesterol with statins can reduce the risk of heart disease and stroke. Conversely, having a high level of HDL-cholesterol is associated with a lower risk of heart disease and stroke. However, it is not clear whether raising HDL-cholesterol reduces the risk of heart disease and strokes.
Clinical trial
A research study conducted with people, usually to evaluate the effect of a treatment or drug. Each trial is designed to answer specific scientific questions and to find better ways to treat people with particular diseases.
Coronary arteries
The arteries (see above) which carry oxygen-rich blood to the heart muscle.
Coronary Artery Bypass Grafting
Coronary Artery Bypass Grafting (CABG) is a surgical procedure that reroutes blood flow around your blocked coronary artery. In the procedure, a transplanted piece of vessel, called a graft, allows blood to 'bypass' the blockage in the artery.
Coronary heart disease
Coronary heart disease is the term used when the coronary arteries become narrowed or 'furred up' by a fatty coating on the inside of the artery. This can result in angina and, sometimes, a heart attack.
Diabetes
A medical condition in which the body cannot control the level of sugar in the blood. This is caused either by a lack of insulin (a hormone in the body which helps control sugar levels in the blood) or resistance to the effect of insulin. In either case this leads to the incorrect regulation of sugar levels in the blood. There are 2 main types of diabetes:
- Type 1 - a form of diabetes which usually starts during childhood, adolescence or early adulthood (also known as insulin-dependent diabetes). It is caused when cells of the immune system attack and kill specific cells in the pancreas (the organ in the body that produces insulin), so that the pancreas makes too little or no insulin at all. The exact cause is unknown, but genetic factors seem to play an important role.
- Type 2 - a form of diabetes that usually starts in middle-age (also known as adult-onset or insulin-resistant diabetes). The cells of the pancreas produce insulin, but the body is unable to use it effectively because the cells of the body are resistant to the action of insulin. This type of diabetes is normally treated by changes in diet, weight control, exercise and oral hypoglycaemic agents (drugs taken by mouth which lower blood sugar levels).
Double-blind study
A kind of clinical study where neither the study participants nor the doctors looking after them know which treatment an individual is taking. This design helps to ensure that the results of the study are reliable and accurate (since neither the doctor nor the patient can affect the observed results with their personal bias about the treatment being studied).
ER (Extended Release) Niacin
ER (extended release) niacin is a formulation of niacin that is absorbed more slowly into your body than normal niacin. This is intended to reduce the intensity of the flushing that often occurs with niacin.
Flushing
This is an uncomfortable feeling of warmth or heat, which may be associated with a 'prickling' sensation and reddening of the skin. In THRIVE study, flushing sometimes occurs soon after taking the tablet ER niacin/laropiprant. Although people find it unpleasant it is not dangerous and if you can persist with taking the tablets the flushing effect usually diminishes with time. Some people find that the flushing is worse if they drink either a hot drink or an alcoholic drink at the same time as taking the tablet(s). If the flushing does settle, it may return if you forget to take your ER niacin/laropiprant for a few days and then restart, so try to remember to take it every day.
Gastrointestinal
Relating to the stomach and intestine.
Heart attack (or myocardial infarction)
This happens when the supply of oxygen-rich blood flowing through one or more of the coronary arteries to the heart muscle is cut off (which is why a heart attack is also sometimes called a coronary). Oxygen is needed to power all our muscles, including the all-important muscle of the heart. If the supply of oxygen is severely reduced, the muscle of the heart indicates this with pain and can then malfunction or cut out.
HDL-cholesterol
A smaller amount of cholesterol is transported in blood as HDL-cholesterol. One role of HDL is to transport excess cholesterol from the tissues (including the walls of arteries) to the liver for disposal. The higher the blood level of HDL-cholesterol, the lower the risk of heart disease. HDL-cholesterol is considered to be the 'good' type of cholesterol.
Heart disease
There are several different types of heart disease. Coronary heart disease is caused by narrowing or 'furring up' of the arteries which supply the heart. In another type of heart disease the heart muscle itself can be abnormal which can cause the heart to pump less effectively. This is sometimes as a result of an enlarged heart muscle which can be caused by high blood pressure.
Laropiprant
Laropiprant is a newly developed drug. It can suppress niacin-induced flushing by blocking the receptor which mediates flushing. In the THRIVE study, it is being used in the combination tablet of ER niacin/laropiprant. The trade name of ER niacin/laropiprant is Tredaptive.
LDL-cholesterol
The majority of the body's cholesterol is transported in blood as LDL cholesterol. The blood level of LDL-cholesterol is strongly associated with risk of CVD: the higher the LDL-cholesterol level, the greater the risk because LDL-cholesterol is deposited in your blood vessels. LDL-cholesterol is considered to be the 'bad' type of cholesterol.
Myopathy
Simvastatin used in THRIVE study, like many other statins can very occasionally cause a muscle problem called 'myopathy'. Myopathy presents with muscle pain and/or weakness (typically in the larger muscles at the top of the legs and arms) with abnormal blood tests. It is uncommon: typically less than 1 in 10,000 people taking simvastatin develop myopathy each year (although it may be more common in people from China). The risk may be increased slightly by taking additional niacin. Myopathy is fully reversible after the simvastatin is stopped as long as it is detected promptly which is why all participants in THRIVE are encouraged to report any unusual muscle symptoms to the study team.
Niacin
Niacin (nicotinic acid, vitamin B3) is part of the normal diet that is essential to various chemical reactions in the body. In larger doses, it also reduces bad cholesterol (LDL-cholesterol) and increases good cholesterol (HDL-cholesterol). In larger doses it can cause flushing in some people and this side effect has limited its use. Flushing can be reduced by changing the formulation of niacin so that it is released more slowly into the body (for example, extended release [ER] niacin). Laropiprant has also been developed to reduce flushing further.
Omega-3 fatty acids (fish oils)
Omega-3 fatty acids are oils high in unsaturated fats, extracted from the bodies of fish or fish parts, especially the livers. These are polyunsaturated fats (i.e. with more than one 'double-bond' in their side chains). The site of the first of these 'double-bonds' whether in the '3' position (as in omega -3 fatty acids) or in the '6' position (as in sunflower oil) determines some of the properties of the oils. As a general rule, unsaturated fats are liquid at room temperature. Olive oil is also an unsaturated oil, but it has just one 'double-bond', and so is sometimes known as a mono-unsaturated fat.
Placebo
A placebo is a dummy tablet which contains no active medication. In THRIVE study the placebo tablets look exactly the same as the active medication.
Random allocation (or randomised)
The treatment a participant receives in THRIVE study (either ER niacin/laropiprantaspirin or placebo and either omega-3 fatty acid or placebo) is randomly allocated by computer. This is a bit like tossing a coin. Each participant will have a 50% chance of receiving active ER niacin/laropiprant and a 50% chance of receiving the placebo ('dummy') tablets, and also a 50% chance of receiving active omega-3 fatty acids and a 50% chance of receiving 'dummy' capsules.
Revascularization
This is the process of restoring the blood supply to a part of the body where the artery was extremely narrowed or blocked. Common sites for revascularization include the heart (coronary) arteries, neck (carotid) arteries and leg arteries. Revascularization can be done surgically or 'percutaneously' via catheters inserted through a small puncture site, usually in the groin.
Statins
A group of medicines (formally known as HMG CoA reductase inhibitors) used to lower the blood level of LDL cholesterol. They are prescribed to treat lipid disorders and also to prevent people at risk of heart diseases or stroke. Statins are very effective at reducing the risk of subsequent vascular events. Simvastatin is one type of statin that all participants in THRIVE will receive.
Stroke
This illness, usually involving loss of movement or feeling on one side of the body, is caused either by the blood supply in the arteries to the brain being blocked (called an 'occlusive' or 'ischaemic' stroke) or by a bleed into the brain (called a 'haemorrhagic stroke' - haemorrhage just means bleed).
Transient ischaemic attack (sometimes called a mini-stroke or TIA)
A short-lived illness (which starts suddenly and normally clears up within 24 hours) of temporary impairment to the brain, resulting in temporary paralysis, numbness and speech difficulty. This is caused by a lack of oxygen supply to the brain due to an obstruction to the arterial blood supply or inadequate blood flow. The loss of blood supply to the brain is most often caused by a clot that forms in a blood vessel within the brain, however it can also result from a clot that forms elsewhere in the body, dislodges from that location, and travels to lodge in an artery of the brain.
Tredaptive
Tredaptive is the trade name for ER niacin/laropiprant which is the drug that is being tested in THRIVE.
Vascular disease
Vascular disease means a disease affecting any of the arteries or veins in the body. Heart disease and stroke are examples of vascular diseases.
Warfarin
An anticoagulant (blood thinning) medicine, used to prevent or slow down the formation of blood clots which can block blood vessels.
