The value of routine non-invasive tests to predict clinical outcome in stable angina.

BACKGROUND Chronic stable angina is a common condition, but considerable differences exist in the likelihood of acute coronary events such as CHD death, non-fatal myocardial infarction (MI) and unstable angina between individual patients. Effective risk prediction is necessary for optimum management. The aim of this study was to identify clinical features and non-invasive test parameters associated with high risk of these coronary events in stable angina and compose a clinically useful model to predict adverse outcomes in this population. METHODS Six hundred and eighty-two patients with stable angina and a positive exercise test (1mm ST depression) from the Total Ischaemic Burden European Trial (TIBET) study, were studied. Resting ECG, exercise tolerance testing and echocardiography were performed at baseline, off anti-anginal therapy. The patients were then randomised to treatment with atenolol, nifedipine or a combination of both. Clinical follow up continued for an average of 2 years (range 1-3 years). RESULTS AND CONCLUSIONS Prior MI or prior CABG were the clinical parameters associated with adverse outcome in patients with stable angina and a positive exercise test. On the ECG, left ventricular hypertrophy was predictive, and on echocardiogram, increased left ventricular dimensions were predictive of adverse events. When combined with time to ischaemia on exercise testing in a simple clinically applicable table these factors could be used to predict of 2 year probability of events for an individual patient.