AUTHOR=Guo Hao-Yang , Wang Wei , Peng Hui , Yuan Hui 

TITLE=Bidirectional two-sample Mendelian randomization study of causality between rheumatoid arthritis and myocardial infarction

JOURNAL=Frontiers in Immunology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.1017444

DOI=10.3389/fimmu.2022.1017444

ISSN=1664-3224

ABSTRACT=Background
Epidemiological evidence suggests an association between rheumatoid arthritis (RA) and myocardial infarction (MI), but causality remains uncertain. Therefore, the purpose of our study was to explore the causal association between RA and MI.
Methods  
Using publicly available genome-wide association study (GWAS) summary datasets, Bidirectional two-sample Mendelian randomization (TSMR) was performed using inverse-variance weighted (IVW), weighted median (WME), MR-Egger regression, Simple mode, and Weighted mode. 
Results  
TSMR results for causal effect of RA on MI (IVW, odds ratio (OR) =1.041, 95% CI: 1.007 ~ 1.076, P=0.017; WME, OR =1.027, 95% CI: 1.006 ~ 1.049, P=0.012) supported the causal association between RA and increased risk of MI; TSMR results for causal effect of MI on RA (IVW, OR =1.012, 95% CI: 0.807 ~ 1.268, P=0.921; WME, OR =1.069, 95% CI: 0.855 ~ 1.338, P=0.556) indicated that there was no causal association between MI and increased risk of RA. 
Conclusion 
Bidirectional TSMR analysis supports the causal association between RA and increased risk of MI but does not support the causal association between MI and increased risk of RA.