The high-risk unstable angina patient. An approach to treatment.

Unstable angina, an intermediate stage in acute coronary ischaemic syndromes, accounts for about 50% of all admissions to the coronary care units in the United States today. It may progress to myocardial infarction in 15% of cases in the first 2 days, and the in-hospital mortality rate is 5%. The pathological hallmark of this syndrome, confirmed by angioscopy, is fissure of the atherosclerotic plaque within the coronary artery, leading to platelet adhesion and aggregation and fibrin-platelet thrombus formation, which may accelerate progression of the stenotic lesion. Management of unstable angina is aimed at ameliorating symptoms and reducing ischaemia, improving ventricular function, preventing recurrent ischaemia, myocardial infarction and death, and lastly, containing progression of the underlying coronary artery disease. Acute management includes bedrest, aspirin, heparin, nitroglycerin (glyceryl trinitrate) infusion and beta-blockers and calcium channel blockers in selected cases. After the patient is clinically stabilised, provocative tests and angiography may be performed, to be followed by angioplasty or bypass surgery, if necessary. In cases that are refractory to optimal medical therapy, interventions should be performed on a more emergent basis. Long term management includes aspirin and beta-blockers, if there is prior infarction, and control of the conventional risk factors.