ABCB1 and atrial fibrillation: However, Liu et al. [5] reported that ABCB1 SNP rs4148738 was not linked to variability in dabigatran concentrations at the peak in AF patients and Sychev et al. [16] showed that there was no influence of the ABCB1 rs4148738 polymorphism on the dabigatran peak and plasma concentrations in 60 patients after knee surgery who received 220 mg dabigatran etexilate once daily for 1 month for the prevention of deep vein thrombosis.