Prognostic value of an electrocardiogram at rest and exercise test in patients admitted with suspected acute myocardial infarction, in whom the diagnosis is not confirmed

The prognosis following discharge in 217 patients admitted with suspected acute myocardial infarction (AMI) due to chest pain, but in whom AMI was not confirmed, was related to the electrocardiogram (ECG) at rest and a symptom-limited exercise test. The patients were followed for 12 to 24 months, (median 14 months). The end-point was a cardiac event, i.e. non-fatal AMI or cardiac death. The prognosis after discharge was only slightly better than in a comparable group of patients with confirmed AMI (P = 0.05). The percentages without a cardiac event after one year were 91.3 and 86.1, respectively. Impaired prognosis was found in patients with negative T waves or ST depression at rest or with ST--T abnormalities or angina pectoris during exercise. Patients with ST depression or elevation, Q wave or intraventricular block at rest. ST abnormalities during exercise or both constituted a high-risk group. The prognosis was significantly better for patients without these entities. The percentage without a cardiac event after one year was 86.9 and 97.6, respectively. It is concluded that patients in whom AMI is not confirmed have a high risk of cardiac events following discharge. Signs of ischaemic heart disease in the ECG at rest and during exercise can be used to identify high and low risk patients.