Does unstable angina still exist?

>The term unstable angina was popularized in the 1970s to describe angina-type symptoms and signs that did not fit into the category of either stable angina or acute myocardial infarction (AMI) and evolved from the term pre-infarction angina. Unstable angina was generally used for the sudden onset of severe chest pain (or change), which was longer in duration than stable angina, occurred without precipitating events, and was not associated with persistent electrocardiogram changes or cardiac biomarker elevation indicative of AMI. The incidence of unstable angina reached a peak in the 1990s, after which use of the term decreased progressively. Some of the factors that contributed to its decreasing incidence include more sensitive cardiac biomarkers, an increasing emphasis on preventative medicine, and the advent of early invasive therapy in high-risk patients. This article reviews the evolution of the term unstable angina, describes some reasons for the decrease in the prevalence of this condition in recent years, and forecasts for discontinuing its use. It appears that patients with ischemic heart disease are now best served by simply dividing them into only two groups, either stable angina or AMI.