Predictors of long term outcome in medically treated patients with unstable angina.

Background: The choice of invasive or noninvasive strategy for low risk patients with unstable angina is a challenge.
Objectives: To investigate the impact of clinical factors on adverse outcomes in patients receiving successful medical treatment and referred from the hospital without invasive procedures.
Methods: The study group consisted of 166 patients (54% men, age 63+/-11 years) who were discharged symptom free after pharmacological treatment of unstable angina. The authors analyzed demographic, clinical, electrocardiographic, echocardiographic and laboratory parameters.
Results: During two years of follow-up, the mortality rate was 4.2%. A composite end point (coronary disease hospitalization, recurrent unstable angina, necessity for revascularization or death) occurred in 99 patients (60%). In multivariate logistic regression, the Canadian Cardiovascular Society (CCS) class (P=0.015) and the left ventricular ejection fraction (P=0.01) were independently predictive for the adverse events. A scoring system was proposed for simple risk stratification, with one point assigned to the patient for CCS class III or IV and left ventricular ejection fraction below 40%, thus yielding a score in the range of 0 to 2. The adverse event rates for total scores of 0, 1 and 2 were 37%, 64% and 86%, respectively.
Conclusions: Uncomplicated follow-up in medically treated patients with unstable angina is rare. Patients with CCS class III and IV or left ventricular ejection fraction below 40% have particularly high rates of recurrent ischemia.