Characterization and prognostic significance of silent myocardial ischemia on predischarge electrocardiographic monitoring in unselected patients with myocardial infarction

Abstract

Characteristics and prognostic significance of ischemic ST changes at predischarge Holter monitoring were evaluated in 270 consecutive postinfarction patients. The 64 patients with ST changes had a greater incidence of non-Q-wave myocardial infarction (p < 0.01) and ventricular premature contractions (p < 0.01); they were more frequently in Moss class > 2 (p < 0.01) and they had a lower wall motion score (p < 0.05). At 2-year follow-up, patients with ST changes had a higher incidence of cardiac death and reinfarction. At multivariate analysis, Killip class (p < 0.01) and ST changes (p < 0.05) were the most predictive variables; when multivariate analysis was repeated including an additional variable—the inability to perform a stress test—Killip class was the most significant variable (p < 0.01), and the presence of ST changes showed only borderline statistical significance (p < 0.1). In the subset of patients who did not perform the stress test, ST change was the most important variable (p < 0.01), followed by Killip class (p < 0.05). Thus, after myocardial infarction, ST changes during Holter monitoring are associated with a poor prognosis and appear useful for stratifying patients who do not perform exercise stress tests.