Seven-year prognostic value of the electrocardiogram at rest and an exercise test in patients admitted for, but without, confirmed myocardial infarction.

Abstract

The seven-year prognosis for cardiac events (non-fatal acute myocardial infarction (AMI) or cardiac death) following discharge was related to an electrocardiogram (ECG) at rest and a symptom-limited exercise test in 217 patients admitted with chest pain without confirmed AMI. The follow-up time was 86-98 months, median 88 months. Although the 7-year prognosis was better than in a comparable group of patients with AMI (P < 0.0001), the frequency of cardiac events was still very high. Patients with negative T waves, ST depression or elevation, intraventricular block or Q waves at rest, ST abnormalities during exercise or both constituted a high-risk group. In patients without these ECG abnormalities the prognosis was significantly better (P << 0.0001). The percentages without cardiac events after 7 years were 53 and 92 respectively. Patients with a low rise in the rate-pressure product indicative of decreased function of the left ventricle and patients who developed angina pectoris during exercise also had a significantly impaired 7-year prognosis. This non-invasive approach to risk stratification identified a group of non-AMI patients with a high risk for cardiac events, and a group comprising more than 50% of the patients with a very low risk.