Abstract
Stable angina is the most common form of presentation of ischemic heart disease, being more common in women (65%) than men (37%), while the reverse is true for the prevalence, being present in about 3.5% of men over 55 as opposed to 1.5% of women. The overall 10 year survival for individuals with stable angina at a mean age of 60 years is 58% for men and 68% for women. Prognosis is related to several factors: age, sex, the number of coronary vessels involved, collateral flow, ventricular function, and the extent of myocardium at risk. It is estimated that stable angina of recent onset is associated with single-vessel disease in about 40% of cases. Angina is a clinical diagnosis but, if doubt exists, one should exclude coronary atherosclerosis or spasm by cardiac catheterization and not rely on noninvasive techniques. Therapy for unstable angina or acute infarction receives considerable attention and is reasonably well defined, but such is not the case for stable angina. Conventionally, it consists of secondary prevention and prescription of nitrates, calcium blockers, or β-blockers. There are several problems: (1) No studies have been performed to assess efficacy in reducing the development of unstable angina. (2) The group of drugs most appropriate for first-line therapy has not been identified. (3) It has not been determined if nitrate tolerance is a major problem. (4) The effect of β-blockers on prognosis in patients with unstable angina has not been defined. (5) A noninvasive means of identifying high and low risk patients with unstable angina has not been developed.