Occurrence, characteristics and prognostic significance of early postacute myocardial infarction angina pectoris

Abstract

To determine the incidence, clinical characteristics and prognostic significance of early spontaneous angina after acute myocardial infarction (AMI), the database involving the 867 participants of the Multicenter Post-AMI Program, who were followed for 1 to 4 years after AMI, was analyzed. Two hundred eighty-six patients (33%) had in-hospital postinfarction angina. During a mean follow-up of 31 months, patients with postinfarction angina were more frequently (p < 0.001) hospitalized for cardiac causes and underwent coronary artery bypass graft surgery; however, their cardiac mortality rates at 1 year (8.4%) and at 4 years (14.3%) were not significantly different from those among patients without postinfarction angina (7.1 and 12.9%, respectively). The only anginal characteristic found to be associated with increased subsequent cardiac mortality (17.9% at 1 year, 39.2% at total follow-up) was high frequency angina (≥1 daily episodes). High frequency angina occurred in a small subset of 28 patients (3.2% of the study population, 9.8% of patients with postinfarction angina). Clinical variables representing higher grades of mechanical dysfunction and electrical instability after infarction were significantly more common among patients with high frequency angina than among those with low frequency angina. Cox survivorship analysis revealed that high frequency angina made a significant contribution to the risk of post-AMI cardiac death (hazard ratio 2.5, p = 0.01), which was independent of the effect of predischarge reduced radionuclide ejection fraction and Holter-recorded frequent or repetitive ventricular premature complexes. Low frequency angina (present in 90.2% of patients with postinfarction angina) did not make a significant contribution to the risk of post-AMI cardiac death (hazard ratio 0.9, p = 0.75).