918 EARLY RECOGNITION OF SUBCLINICAL ATRIAL FIBRILLATION IN PATIENTS IMPLANTED WITH DIFFERENT DEVICES


 
 
 Atrial fibrillation (AF) is the supra-ventricular tachyarrhythmia mostly encountered in the clinical practice.While appearing silent or with a constellation of symptoms, it confers a 5-fold risk of stroke. Early detection is mandatory to establish the diagnosis and recommend anticoagulation. Besides the arrhythmia recognition through several tools, such as Holter ECG and loop recorders, it has been underlined that cardiac implantable electronic devices with an atrial lead can help in recognizing asymptomatic AF periods, also known as atrial high-rate episodes (AHREs).
 
 
 
 48 patients with AHRE detection at device telemetry checks were enrolled; implanted device were pacemakers (n=31, 64.8%); implantable cardioverter/defibrillators (ICD, n=8, 16.6%); cardiac resynchronization therapy devices with defibrillators (CRT-D, n=9, 18.5%). Male gender was predominant (40 vs. 8), age was > 65years, and mean CHA2DS2VASc was 4.2±2.8. Patients underwent ECG assessment in 6-month intervals (at baseline and during follow-up), MOntreal Cognitive Assessment test, and device interrogation for AHRE of duration >5 minutes and rate >175 beats per minute. Randomization to a direct oral anticoagulant (DOAC) or usual care (aspirin when needed or placebo) was provided in a blind fashion and maintained for the entire study observation until occurrence of overt AF, followed by exclusion from the study.
 
 
 
 We found that 13%-16% of patients with device-detected AHRE developed AF over a mean follow-up of 2.5 year (range 4.6±2.0). These cases were given oral anticoagulation since change of indication according to current guidelines. Most important comorbidities were coronary artery disease (n=18 patients, 36.73%); systemic hypertension (n=41, 83.67%); diabetes (n=13, 26.53%); dyslipidemia (n=23, 46.8%); heart failure (n=17, 35.4%). 30 patients were treated with beta-blockers(62.5%). 2 patients died for gastrointestinal bleeding. One patient was excluded for major bleeding after one month from the enrollment. Total AHREs duration was significantly lower in patients with pacemaker (14 hrs) compared to patients with CRT-D (17 hrs) and ICD (20 hrs, p<0.05).
 
 
 
 The impact of AHREs was higher in patients affected by cardiac dysfunction and concomitant diseases; none of the patients enrolled in the study developed ischemic stroke; major bleedings were observed in both arms. Further studies are warranted for considering oral anticoagulation based on the sole device interrogation in the context of subclinical atrial fibrillation.
