A study published in the European Journal of Preventive Cardiology provides “strong evidence” of a causal relationship between elevated blood pressure and atrial fibrillation (AF). Authors of the study suggest that strict blood pressure control measures could be an effective strategy to prevent AF and its associated complications.
The study used Mendelian randomisation to investigate whether blood pressure has a direct impact on the risk of AF.
Genetic variants associated with blood pressure traits were taken from the International Consortium of Blood Pressure Genome Wide Association Studies (GWAS), the largest genome-wide association study (GWAS) on blood pressure and AF, which included more than one million individuals of European ancestry—of which 60,620 had AF and 970,216 did not.
The first step was to identify 894 genetic variants associated with blood pressure. Next, the researchers analysed which of those variants play a role in AF.
To conduct the naturally randomised controlled trial, the 894 genetic variants were randomly allocated to all participants at conception, giving each individual a blood pressure level. The investigators then analysed the association between blood pressure and AF.
Elevated blood pressure was associated with an increased risk of AF. Specifically, 1mmHg rises in systolic blood pressure, diastolic blood pressure and pulse pressure were associated with 1.8%, 2.6% and 1.4% relative increases in the risk of AF, respectively.
Study author Georgios Georgiopoulos (King’s College London, UK and National and Kapodistrian University of Athens, Greece), said: “Establishing that elevated blood pressure causes AF provides further impetus for public health strategies aimed at improving blood pressure control in the general population and for individual efforts to keep levels in check.”
Georgiopoulos added: “The results provide strong evidence of a causal relationship between blood pressure and AF. Using genetic information in the analyses minimises the likelihood of reverse causality (i.e. that AF causes high blood pressure) or that other traits linked with AF (confounders) were responsible. Our study showed that the relationship was not driven by other conditions including coronary artery disease and obesity.”
He concluded: “Our findings confirm the hypothesis that AF is preventable. This indicates that strict blood pressure control could be an effective strategy to stop AF and its complications, which include stroke, heart failure, dementia, and depression.”