AUTHOR=Yang Zhi-Qiang , Fan Ting-Ting , Wang Zheng , Zhou Wan-Ting , Wang Zhen-Xian , Tan Yan , Wu Qi , Xu Bang-Long 

TITLE=Causal associations between blood pressure and the risk of myocardial infarction: A bidirectional Mendelian randomization study

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2022.924525

DOI=10.3389/fcvm.2022.924525

ISSN=2297-055X

ABSTRACT=Introduction:
Many observational studies suggest elevated blood pressure (BP) as a leading risk factor for incident myocardial infarction (MI), but whether this relationship is causal remains unknown. In this study, we used bidirectional Mendelian randomization (MR) to investigate the potential causal association of BP levels with the risk of MI.
Methods:
  Genetic variants associated with BP traits were retrieved from the International Consortium of Blood Pressure (N= 757601) and NA (N= 361194), obtaining 12640541 variants. We used two-sample MR (TSMR) analyses to examine the potential bidirectional causal association of systolic BP (SBP) and diastolic BP (DBP) with MI.
Results:
  The forward MR analysis identified a potentially causal association between MI and BP [odds ratio (OR) SBP: 1.0008, 95% confidence interval (CI): 1.0006–1.0009, P=1.911×10−22; ORDBP: 1.0014, 95% CI: 1.0011–1.0016, P= 1.788×10-28]. However, the reverse analysis suggested no causal relation (betaSBP: 5.469, P=0.763; betaDBP: 3.624, P=0.588). These findings were robust in sensitivity analyses such as the MR–Egger method, the maximum likelihood method and the MR pleiotropy residual sum and outlier test (MR-PRESSO). No horizontal pleiotropy (p = 0.869 for SBP, p = 0.109 for DBP in the forward results and p = 0.168 for SBP, P= 0.892 for DBP in the reverse results) was observed.
Conclusions:
Elevated BP levels increase the risk of MI, but there is no causal relationship between MI and changes in BP. Independent of other risk factors, optimal BP control might represent an important therapeutic target for MI prevention in the general population.