Bidirectional association between abnormal cardiac conditions and epilepsy: A two-sample Mendelian randomization study

Background

Observational studies have consistently indicated a significant correlation between abnormal cardiac conditions and epilepsy. However, the association and direction of this relationship remain a subject of debate. This study employs a two-sample bidirectional Mendelian randomization (MR) approach to investigate the association between abnormal cardiac conditions and epilepsy.

Methods

Instrumental variables, represented by single nucleotide polymorphisms (SNPs) associated with epilepsy and various abnormal cardiac conditions, were derived from large-scale genome-wide association studies databases, including FinnGen and UK Biobank. Bidirectional MR analysis was conducted to estimate the association between epilepsy and abnormal cardiac conditions. Sensitivity analyses were performed using MR-Egger, weighted median, Inverse Variance Weighted, and MR pleiotropy residual sum and outlier methods.

Results

The forward MR analysis suggested a potential positive effect of atrial fibrillation and flutter (AF) and valvular heart diseases (VHD) on the risk of epilepsy. Conversely, the reverse MR analysis indicated that epilepsy might increase the susceptibility to AF, VHD, and heart failure.

Conclusion

The findings support a bidirectional relationship between AF, VHD, and epilepsy, indicating that AF and VHD can elevate the risk of developing epilepsy, while epilepsy, in turn, can also increase the risk of developing AF and VHD. Furthermore, the study suggest that epilepsy may contribute to the development of heart failure. These results underscore the importance of screening for cardiac abnormalities in patients with epilepsy and vice versa, to better understand their clinical significance and potential as modifiable risk factors.