[Long-term prognosis in unstable angina]

The expression unstable angina pectoris covers a wide range of clinical symptoms with different pathogenetic mechanisms and clinical outcome. Several forms of unstable angina pectoris, in particular progressive angina pectoris (crescendo angina) with chest pain at rest in a previously asymptomatic patient, progressive angina pectoris with chest pain at rest in a previously symptomatic patient, and chest pain at rest of at least 15 min duration without obvious trigger mechanisms have been distinguished. In simpler terms: one may also distinguish angina pectoris of recent onset, crescendo angina, and acute coronary insufficiency. Four risk factors appear to determine the prognosis in these patients: exercise-induced angina pectoris, multiple episodes of chest pain before hospitalization, electrocardiographic changes, and recurrent angina pectoris during hospitalization. Acute coronary insufficiency and nontransmural infarction have initially better prognosis than transmural infarction; however, recurrent cardiac events are more frequent in patients with nontransmural infarction, particularly in the elderly with persistent ECG changes, cardiac decompensation, and infarct extension. Unstable angina pectoris and myocardial ischemia after myocardial infarction are generally associated with a poorer prognosis. In contrast, recurrence of angina pectoris after PTCA (within the first six months) is most commonly due to restenosis and hence prognostically not of great importance. Unstable angina pectoris after coronary bypass surgery, however, is a prognostically unfavourable sign. Prognosis in patients with Prinzmetal angina is determined by the extent of coronary disease. In summary, long-term prognosis in patients with unstable angina pectoris depends heavily on the clinical presentation and the previous clinical history of the patient.