Moxifloxacin-induced changes in T-wave morphology

Abstract

Electrocardiographic (ECG) criteria for acute myocardial ischemia that may lead to myocardial infarction (MI) have recently been revised, in part to address gender differences. To assess the performance of these revised ECG criteria, we studied 154 patients presenting to the emergency department (ED) with symptoms of possible ischemia, but a nondiagnostic initial ECG by prior standard criteria. Final diagnostic categories included acute MI (n = 51), unstable angina (UA) (n = 52), and noncardiac chest pain (n = 51). The 3 groups were matched for age and sex. Electrocardiograms were read by a single board-certified cardiologist in a blinded fashion several months apart, using first the standard criteria and then the revised criteria. In 24 subjects (16%), the initial nondiagnostic ECG was now suggestive of ischemia using the revised criteria. Seventeen (71%) of these 24 subjects left the hospital with a final diagnosis of MI, 6 were diagnosed with UA (25%), but only 1 (4%) left with a diagnosis of noncardiac symptoms. In logistic regression analysis, ischemic ECG changes were strongly associated with a final diagnosis of MI or UA (odds ratio, 14.4; P = .01). At follow-up, 12 (9%) of 140 subjects with 1-year follow-up had died. Having ischemic changes by the revised criteria was associated with a higher risk of death in χ analysis (20% versus 7%, P = .05), but not of recurrent ED visits or hospital admission. After adjustment for age, sex, standard cardiac risk factors, and a history of coronary artery disease, ischemic ECG changes were associated with an more than 3-fold increase in the risk of death (odds ratio, 3.6) but were no longer an independent predictor (P = .1). The strongest predictor of both recurrent ED visits and hospital admission was a history of coronary artery disease. Conclusion: In subjects presenting to the ED with symptoms of possible cardiac ischemia and a previously nondiagnostic ECG, revised ESC/ACCF/ AHA/WHF ECG criteria identify substantially more patients ultimately diagnosed with an acute coronary syndrome. These patients have increased 1-year mortality.