A heart attack (myocardial infarction) occurs when the supply of blood and oxygen to an area of heart muscle is blocked, usually by a clot in a coronary artery. Clinical research involves investigations into the molecular, genetic and environmental causes of coronary artery disease and myocardial infarctions. Also includes: new therapies to treat patients diagnosed or at risk of acute coronary syndromes including heart attack and unstable angina pectoris (accelerating chest pain or angina), interventional cardiology (angioplasty, stents) for the treatment of acute coronary syndromes, and anti-thrombotic therapies.