Regular review: Treatment possibilities for unstable angina

Unstable angina is frequently encountered by general practitioners and cardiovascular specialists. In the United States, of the 2.5 million patients admitted to hospital every year with suspected acute coronary syndromes, 1.5 million have unstable angina. The rest have myocardial infarction with or without ST elevation. 1 Earlier published literature classified acute ischaemic episodes as unstable angina and either non-Q wave or Q wave infarction. As Q wave and non-Q wave infarctions can only be definitely distinguished by electrocardiography several days after the clinical event, the classification does not help with emergency patients. Moreover, the prognostic value of Q wave versus non-Q wave infarction classification is limited. 2 A new nosological scheme has derived from the need to rapidly assess patients at presentation so that powerful new treatments can be appropriately selected. All acute presentations suggesting acute coronary syndromes can be further divided into infarction with ST elevation (possibly including patients with new bundle branch blocks) and infarction without ST elevation and unstable angina combined. The distinction between the last two conditions can be reliably made by measuring serum markers. This classification makes sense because early thrombolytic treatment saves the lives of patients with infarction with ST elevation but has no beneficial, and probably some deleterious, effect in those with infarction without ST elevation or unstable angina. Moreover, the therapeutic approaches in the last two conditions are similar. Hence we consider unstable angina and infarction without ST elevation as a single entity, especially regarding treatment.