Non Vitamin k Antagonist Oral Anticoagulation Assessment in Non Valvular Atrial Fibrillation Using Transcranial Doppler Ultrasonography

: Background : Warfarin with optimized international normalization ratio (INR); is significantly affect the Micro embolic signals (MES), in many studies. Non vitamin k antagonist oral anticoagulants (NOACs) are recently approved for stroke prevention in non valvular AF. In contrast to Warfarin; effect of NOACs on MES is not yet fully researched. Aim : To determine the effect of NOACs on MES, in comparison to warfarin in non valvular AF, to reflect the potential embolization risk. Methods : The incidence and number of MES was studied in patients with non valvular AF. Two groups in the current study; the first, patients were put on warfarin with INR levels were optimized to (2-3), and considered as a control group. The second; patients were put on NOAC (rivaroxaban, 15 mg /day). Study patients were recruited from cardiology outpatient clinics and departments (Al-Azhar University hospitals; Cairo and New Damietta, Egypt). Patients of the both groups were subjected to MES detection and counting by transcranial Doppler ultrasonography (TCD) monitoring. Results : MES did not detected in 22.5% in study groups; no statistically significant differences between study groups. The incidence and number of MES; within the warfarin group; MES were detected in (30 patients, 75%), while within the rivaroxaban group (32 patients, 80%). The average number of MES; in group one were (11.65 ±7.20), and in group two (11.50 ±7.20), with no significant statistical difference also. Conclusion : The effect of warfarin and NOAC use is not statistically different and Rivaroxaban is not inferior to warfarin.