Silent ischemic brain lesions detected by multi-slice computed tomography are associated with subclinical atrial fibrillation in patients with cardiac resynchronization therapy with subclinical atrial fibrillation in patients with cardiac resynchronization therapy

Introduction
There is insufficient research on the relationship between subclinical atrial fibrillation (SCAF) and silent ischemic brain lesions (IBLs).

Aim
To investigate the relationship between SCAF and silent IBLs in patients with cardiac resynchronization therapy (CRT).

Material and methods
Of 720 CRT implanted patients in our department between 2012 and 2018, 121 patients who underwent elective cranial multi-slice computed tomography (MSCT) during their follow-up were included in our study. Atrial high-rate episodes (AHRE) were detected by the CRT device. Subclinical atrial fibrillation was defined as asymptomatic AHRE longer than 6 min and shorter than 24 h. A cranial MSCT scan was performed using a 128-section scanner with contiguous 2–5 mm axial images. Patients were divided into two groups – with and without silent IBL.

Results
Silent IBLs were detected in 21 (17.4%) of 121 patients with CRT. Ischemic brain lesion presence was found to be associated with age, CHA2DS2-VASc score, left ventricular (LV) ejection fraction (EF), hypertension and SCAF in univariate analysis (p < 0.05). In multivariate regression analysis, presence of SCAF and LVEF were found to be independent parameters predicting the risk of silent IBLs. According to this analysis, the presence of SCAF and every 1% decrease in LVEF were found to increase the risk of silent IBL by 3.5 times and 14.8%, respectively.

Conclusions
Subclinical atrial fibrillation is independently associated with silent IBL presence. Patients with CRT should be closely monitored for SCAF. Patients diagnosed with SCAF should be evaluated for IBL development and treated with the appropriate oral anticoagulant.