Usefulness of hospital admission risk stratification for predicting nonfatal acute myocardial infarction or death six months later in unstable anginapectoris

The aim of this study was to assess the clinical course of unstable angina and the prognostic value of clinical and electrocardiographic variables mea sured during admission in a prospective, multicenter cohort study with 6-mo nth follow-up. The population corresponds to 4 general teaching hospitals i n Catalonia, Spain. The clinical course was analyzed in 839 consecutive pat ients aged up to 80 years with primary unstable angina, without myocardial infarction or previous coronary bypass. The main outcome measures were card iac mortality and nonfatal myocardial infarction. Patients involved in the present analysis belonged to the Resources Used in Acute Coronary Syndromes and Delays in Treatment (RESCATE) study. Six-month overall mortality, card iac mortality, and nonfat-al myocardial infarction rates were 4.6%, 4.1%, a nd 3.9%, respectively. Six-month cardiac mortality or myocardial infarction rate did not differ among clinical forms of presentation. Peripheral arter y disease (RR 3.5, 95% confidence interval [Cl] 1.88 to 6.50, p = 0.0001), ST-T-wave electrocardiographic changes on admission (RR 2.22, 95% Cl 1.13 t o 4.36, p = 0.0203), and age >65 years (RR 1.74, 95% Cl 1.04 to 2.91, p = 0 .0356) independently predicted 6-month cardiac mortality or nonfatal myocar dial infarction. Their positive predictive values were 21%, 10%, and 11% re spectively, whereas their negative predictive value was greater than or equ al to 93% in all cases. Prevalences were 9%, 70%, and 41%, respectively. In this prospective study, patients with unstable angina without prior myocar dial infarction have a relatively low, although not negligible, 6-month sev ere complication rate. Stratification risk can easily be established with c linical and electrocardiographic characteristics measured during admission. Their absence almost rules out future adverse events, while their presence does not necessarily imply bad prognosis. (C) 1999 by Excerpta Medica, Inc .