Predictors and outcomes of atrial tachyarrhythmia among patients with implantable defibrillators

Background Atrial tachyarrhythmias (ATAs) are common among heart failure (HF) patients. Objective The purpose of this study was to assess predictors for the development of new ATA and its components (atrial fibrillation/flutter [AF], supraventricular tachycardia [SVT]), and their association with subsequent clinical outcomes. Methods We assessed predictors for first and recurrent ATA, AF, and SVT among 1500 patients in MADIT-RIT (Multicenter Automatic Defibrillator Implantation Trial–Reduce Inappropriate Therapy). We also investigated the association of new ATA, AF, or SVT with subsequent ventricular arrhythmia (VA), adverse events (HF hospitalization, syncope, or death), or death by time-dependent analysis. Results During 17 months of follow-up, 286 patients (19%) developed new ATA, of whom 92 (6%) had AF and 194 (12%) had SVT. Younger age (≤65 years), diastolic blood pressure ≥72 mm Hg, heart rate ≥63 bpm, absence of diabetes, and prior atrial arrhythmia were independent predictors of ATA. Prior atrial arrhythmia was the only predictor of AF (hazard ratio 3.14; P 2-fold increased risk for the development of subsequent VA (HR 2.21; P = .012l and HR 2.15; P Conclusion Among MADIT-RIT patients, younger age, absence of diabetes, higher blood pressure, higher heart rate, and prior atrial arrhythmia predicted device-detected ATA. Both AF and SVT were associated with increased risk for subsequent VA and adverse events. Aggressive management should be considered in HF patients who develop new-onset, device-detected ATA to improve clinical outcomes.