Abstract 2300: Incidence of Life-threatening Ventricular Tachyarrhythmias in Patients with Coronary Artery Disease and Prophylactic Implantable Defibrillator: Results from a Prospective Multicenter Study
Objectives: The results of the MADIT - 1 and MADIT - 2 studies demonstrated that primary prophylaxis with an implantable cardioverter defibrillator (ICD) in patients with former myocardial infarction and severely reduced left ventricular ejection fraction (LVEF) reduces mortality. The aim of this study was to assess the incidence and characteristics of spontaneous ventricular tachyarrhythmias after prophylactic ICD implantation in a multicenter study with 200 consecutive patients.
Design: Prospective observational study.
Patients: 200 consecutive patients from three medical institutions who fulfilled MADIT 1 or 2 criteria and received a prophylactic ICD.
Results: During a mean (SD) follow up of 22 +/− 15 months 68 of 200 patients (34%) experienced at least one spontaneous episode of VT/VF. The mean (SD) time to the first event was 11.8 (12.5) months. Monomorphic ventricular tachycardia (VT) occurred in 27% of the patients and at least one episode of primary ventricular fibrillation (VF) in 19% of all patients. Primary ventricular fibrillation and monomorphic ventricular tachcardia was documented in 12 % of all patients. The mean (SD) cycle length of all episodes was 315 (58) ms, the mean (SD) cycle length of monomorphic VT was 327 (60)ms, VF 227 (99) ms. 80 % of all tachyarrhytmias were successfully terminated by antitachycardia pacing and 16 % by shock therapy.
The incidence of spontaneous ventricular tachycardia or ventricular fibrillation in a large patient population with prophylactic ICD is 34%.
The vast majority of tachyarrhytmia episodes are monomorphic VT of which 80 % could be successfully terminated by antitachycardia pacing.
The data support prophlactic use of ICDs in patients with prior MI and severely reduced LV function and underline the need of antitachycardia pacing.