Clinical Impact of Arrhythmias Detected by an Implantable Cardiac Monitoring Device With Real-Time Transmission Among Patients With Early Reduced Left Ventricular Ejection Fraction After ST-Segment Elevation Acute Myocardial Infarction: The TeVeO Study.

BACKGROUND: Modern therapeutic strategies have reduced mortality after a ST-segment elevation acute myocardial infarction (STEMI). However, up-to-date information on the incidence and prognostic impact of arrhythmias following this event is lacking. OBJECTIVES: This study sought to evaluate the incidence and clinical impact of ambulatory arrhythmias detected by an implantable cardiac monitor (ICM) using Bluetooth connectivity and remote monitoring after STEMI. METHODS: The TeVeO study was a multicenter, prospective study of patients who survived STEMI with reduced left ventricular ejection fraction (LVEF). Patients underwent continuous electrocardiographic monitoring using an ICM after discharge. Indication for implantable cardioverter-defibrillator (ICD) placement for primary prevention was evaluated at 6 months. RESULTS: A total of 3,565 patients were hospitalized for STEMI and subsequently discharged from our institutions. Of these, 636 had an LVEF ≤40% on day 4 or later. After application of the inclusion and exclusion criteria, 224 patients (35%) were enrolled (median LVEF: 35%). After a median follow-up time of 3.1 years, the mortality rate was 3.7 per 100 patient-years. No cases of sudden arrhythmic death were observed. At 6 months, an ICD was implanted in 25 (11%) patients (23 for primary prevention, 2 for secondary prevention). During follow-up, 119 patients (53%) experienced at least 1 ambulatory arrhythmia: 39 (17%) atrial fibrillation (AF), 35 (16%) nonsustained ventricular tachycardia, 33 (15%) sinus pauses >3 seconds, 14 (6%) second-or third-degree atrioventricular block, and 5 (2.2%) sustained monomorphic ventricular tachycardia/appropriate ICD therapy. The incidence rate of nonsustained ventricular tachycardia was 5.4 and for sustained monomorphic ventricular tachycardia/appropriate ICD therapy 0.9 per 100 patient-years. Only AF was independently associated with increased mortality (adjusted HR = 2.5; P = 0.04). CONCLUSIONS: The incidence and burden of ventricular arrhythmias were lower than expected. AF was associated with an increased mortality.