Clinical and electrocardiographic variables predictive of early and late outcome in unstable angina

ABSTRACT

Fifty patients with unstable angina were studied to define the clinical and electrocardiographic variables predictive of outcome. Based on clinical presentation, patients were stratified into the following types IA [new onset angina], IB [crescendo angina], IC [angina at rest], II [prolonged angina 20 minutes with ST-T changes on EKG], III [post infarction angina]. Patients were divided into two groups according to the occurrence of complications as acute myocardial infarction, serious arrhythmia [ventricular tachycardia or fibrillation] or death. Nine patients developed complications [group II], five had AMI and four died. Treadmill exercise testing was done in 19 patients if resting EKG was normal or after improvement. Silent ischemia was present in 11, all had no complications and symptomatic [painful] ischemia was noted in eight, two of them were among the complicated group. Patients with unstable angina managed in hospital have an incidence of AMI or death of 18% during a follow-up period of 1 to 27 months [mean 9 +/- 7]. Predictors of a worse prognosis were older age, presence of prolonged chest pain and heart failure. A point score system was developed for better prediction of outcome depending on the following clinical and electrocardiographic variables Age, history of hypertension, smoking cigarettes, diabetes mellitus, hyperlipidemia, chest pain duration of 20 minutes or more, presence of previous infarction and/or presence of EKG ST-T changes, ventricular premature beats, elevated cardiac enzymes, presence of heart failure. A point value of 0 or 1 is assigned to each variable 0 = absent, 1 = present. Each patient's total score was determined by summing the point values of the 10 variables. A score of 5 or more increased the predictive value of a complicated course. Treadmill exercise testing in some of these patients revealed that silent ischemia does not have a worse prognosis than painful or symptomatic ischemia. It was concluded that this score system helps for better prediction of the course of unstable angina and for selection of patients to be admitted to ICU