Predictors and Outcomes of Atrial Tachyarrhythmia among Patients with Implantable Defibrillators.

BACKGROUND: atrial tachyarrhythmia (ATA) are common among heart failure (HF) patients.

OBJECTIVE: to assess predictors for the development of new (ATA), and its components (atrial fibrillation/flutter [AF], or supraventricular tachycardia [SVT]), and the association with subsequent clinical outcomes.

METHODS: In 1500 MADIT-RIT patients, we assessed predictors for first and recurrent ATA, AF and SVT. Furthermore, we investigated the association of new ATA, AF, or SVT, with subsequent ventricular arrhythmia (VA), adverse events (HF hospitalization, syncope, or death), or death in time-dependent analysis.

RESULTS: During 17 months of follow-up, 286(19%) patients developed new ATA, of whom 92(6%) had AF and 194(12%) had SVT. Younger age ≤ 65 years, diastolic blood pressure ≥ 72 mmHg, heart rate ≥ 63 bpm, absence of diabetes and prior atrial arrhythmia were independent predictors for ATA. Prior atrial arrhythmia was the only predictor for AF (HR=3.14; p<0.001). New ATA was associated with significantly increased risk for subsequent VA (HR=2.12; p<0.001), increased adverse events (HR=1.42; p<0.001) and death (HR=1.85; p=0.038). New AF and new SVT were both independently associated with >2-fold increased risk for the development of subsequent VA (HR=2.21; p=0.012 and HR = 2.15; p<0.001, respectively) and adverse events.

CONCLUSIONS: In 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 heart failure patients who develop new onset, device detected ATA to improve clinical outcomes.