Remote monitoring and early detection of sub-clinical atrial fibrillation in implantable cardioverter defibrillator recipients: incidence, risk factors and prognostic significance (Preprint)

BACKGROUND Atrial high rate episodes (AHREs) detected by cardiac electronic implantable devices are common. They are significantly associated with mortality and morbidity due to systemic embolism and ischemic stroke. Much earlier detection of AHREs might allow the timely introduction of therapies to protect the patient. OBJECTIVE The aim of this study was to determine the incidence and risk factors of AHREs in patients with implantable defibrillator in the era of remote monitoring (RM), and to analyze the choice of anticoagulant treatment strategies and its potential complications. METHODS 1226 patients with implantable cardioverter defibrillator remotely followed-up were prospectively included from January 2009 to December 2016 at Lille University Hospital. The first phase of the study focuses primarily on the incidence and risk factors of AHREs and the second analysis was confined to patients presenting at least one AHRE. Survey analysis was determined using the Kaplan-Meier method and compared between groups with the Logrank test. RESULTS Among the 1226 patients, 63 presented at least one AHRE detected by RM which corresponds to an incidence of 5.14%. In ¾ of cases, the AHRE was completely asymptomatic. In the remaining quarter, the most common symptom was dyspnea. The main precipitating factor was infection. AHRE risk factors were thyroid dysfunction (p = 0.0047) and left atrial enlargement (p = 0.0317). None of these factors were associated with atrial fibrillation duration. The mean CHA2DS2-VASc score was 2.64 ± 1.38. Oral anticoagulation therapy was introduced in 47 patients (88.7%). The incidence of thromboembolic events was 1.6% and that of anticoagulation-related hemorrhagic complications was 8.5% (n = 4) with ¾ major. CONCLUSIONS AHRE is a common disease. Risk factors are thyroid dysfunction and left atrial enlargement. Its thromboembolism risk seems to be low. The introduction of anticoagulation therapy is based on the evaluation of clinical risk scores for systemic embolism and its indication must be regularly assessed because hemorrhagic complications are common.