Clinical Outcome and ECG Change in Patients with Acute Myocardial Infarction and Prodromal Angina

ABSTRACT

BACKGROUND AND OBJECTIVES: Ischemic preconditioning reduces the size of myocardial infarct in animal models, however its role in humans remains unclear. Clinical data suggests that episodes of angina immediately before acute myocardial infarction may be associated with a protective effect on the human myocardium. We performed an analysis on the effect of prodromal angina on infarct size, in-hospital outcome and newly developed Q-wave in patients with acute myocardial infarction. SUBJECTS AND METHODS: 65 patients who had received thrombolytic therapy were enrolled in the study. Eleven patients (17%) had experienced previous angina within 24 hours prior to acute myocardial infarction (group I), and the remaining 54 patients (83%) did not have a history of previous angina (group II). Killip class, cardiac enzyme, ECG findings, echocardiographic data and in-hospital outcomes were compared between the two groups. RESULTS: Group I tended to have lower peak creatine kinase (CK) and CK-MB levels, although the difference between the two groups in regards to the level of cardiac enzyme was statistically insignificant. Despite similar patient characteristics, Group I showed a lower incidence of heart failure during hospitalization than group II. 6/11 patients (55%) in group I and 47/54 (87%) in group II had a Q-wave at discharge ECG. Group I showed better left ventricular systolic function during admission. None of the DM patients (14 patients) had prodromal angina and 13 of 14 patients (93%) demonstrated Q-wave infarction. CONCLUSION: Prodromal angina prior to acute myocardial infarction as a marker of ischemic preconditioning may also confer beneficial effects in terms of in-hospital outcomes. Further studies concerning the long term outcomes of such cases are needed.