Sun X, Lu Y, Wang Z, et al. - Researchers sought to ascertain whether there exists a causal link between homocysteine (Hcy) and atrial fibrillation (AF), by performing this Mendelian randomization (MR) study. From a genome-wide meta-analysis (N = 44,147), they obtained single-nucleotide polymorphisms (SNPs) which genome-wide significantly related to plasma Hcy concentrations. MR analyses were performed to estimate the links between the selected SNPs and AF on the basis of a meta-analysis of genome-wide association study for AF (N = 588,190). According to the findings, plasma Hcy concentrations were not causally related to AF.