Research Letter: Genetically determined blood pressure traits are associated with increased risk of aortic dissection: a Mendelian randomization study

Objective To identify blood pressure traits influencing aortic dissection susceptibility using Mendelian randomization (MR). Methods Summarys: tatistics of AD genome-wide association studies (GWAS) was obtained from FinnGen R5 release, which included 470 individuals with AD and 206541 controls. Firstly, inverse variance weighted (IVW) was used to calculate the overall OR for blood pressure traits. Further, directional pleiotropy and heterogeneity were tested as well as MR pleiotropy residual sum and outlier (MR-PRESSO) method. Results Positive associations were observed between DBP (OR=1.13, 95%CI 1.09-1.18, P-adjusted < 0.001), hypertension (OR=9.71, 95%CI 2.45-38.25, P-adjusted = 0.006) and AD. Further, there was potential causal relationship between MAP and AD (OR=1.15, 95%CI 1.02-1.30, P-unadjusted = 0.020). No significant association between SBP or PP and AD in the European populations were observed. No directional pleiotropy was observed. Heterogeneity was only detected in the genetic instruments for SBP (Cochran’s Q statistics = 491.7, P = 0.010). The MR-PRESSO suggested one outlier SNP for SBP and one for PP which did not affect the result above. Conclusion In this study, we identified a forward causation between hypertension, SBP and AD. In addition, there were nominal significant causations between MAP and AD. No significant causal relationships were detected between other investigated blood pressure traits (SBP, PP) and AD.