T-Wave Alternans Is Linked to Microvascular Obstruction and to Recurrent Coronary Ischemia After Myocardial Infarction

The purpose of this study is to investigate the relationship between T-wave alternans (TWA), infarct size and microvascular obstruction (MVO) and recurrent cardiac morbidity after ST elevation myocardial infarction (STEMI). One hundred six patients underwent TWA testing 1–12 months and 57 patients underwent cardiac magnetic resonance imaging (MRI) in the first 2–4 days after STEMI. During follow-up (3.5 ± 0.5 years), death (n = 2), ventricular tachycardia (n = 3), supraventricular tachycardia (n = 4), heart failure (n = 3) and recurrent coronary ischemia (n = 25) were observed. After multivariate analysis, positive TWA (HR2.59, CI1.10-6.11, p0.024) and larger MVO (HR1.08, CI1.01-1.16, p0.034) were associated with recurrent angina or ACS. Presence of MVO was correlated with TWA (Spearman rho 0.404, p0.002) and the impairment of LVEF (−0.524, p < 0.001). Patients after STEMI remain at a high risk of symptoms of coronary ischemia. The presence of MVO and TWA 1–12 months after STEMI is related to each other and to recurrent angina or ACS.