[Unstable angina pectoris. Pathogenesis, treatment and prognosis].

Unstable angina pectoris is a term used for various clinical conditions of angina pectoris, such as new onset of angina, accelerated angina, resting angina and post-infarction angina. The natural history varies according to clinical presentation, and the prognosis differs considerably for the different types of unstable angina. The first step in the pathophysiological mechanisms leading to unstable angina is thought to be rupture of an atherosclerotic plaque. Exposure of the content of the plaque leads to varying degrees of coronary obstruction, due to coronary thrombosis and vasoconstriction. A key element is dysfunction and activation of the endothelium. Patients with unstable angina should be hospitalized and treated with anti-anginal drugs, and with aspirin and heparin to reduce risk of myocardial infarction. Coronary angiography should be considered to identify patients who might benefit from angioplasty or coronary bypass surgery. Reduction of risk factors is important for long-term outcome.