Genetic study indicates causal link between high BP and risk of AF
February 10, 2021
2 minutes to read
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Disclosures: The authors do not report any relevant financial disclosures.
In a Mendelian randomization study, high systolic BP, diastolic BP, and pressure differential were each associated with an increased risk of atrial fibrillation.
âHigh blood pressure is one of the most common and strongest risk factors associated with the risk of AF. Despite this evidence, the association between hypertension and AF could be subject to several confounding factors, as they are both diseases related to aging and generally associated with other cardiovascular risk factors, including obesity, diabetes, inflammation and dyslipidemia. Georgios Georgiopoulos, MD, M.Sc., Ph.D., of the School of Biomedical Engineering & Imaging Sciences at King’s College London and the Department of Clinical Therapy at the National and Kapodistrian University of Athens School of Medicine, and colleagues have written. âUsing Mendelian randomization, we now provide the first evidence that the relationship between elevated BP and AF risk is likely causal. Importantly, the association between BP values ââand AF risk was not limited to systolic BP, but also involved diastolic BP and pulse pressure.
For analysis, the researchers obtained genetic variants associated with PA from the International Consortium for Genome-wide Association Studies of Blood Pressure. A total of 894 variants were evaluated in a genome-wide association study of AF genetics that included more than one million participants of European descent. Researchers conducted Mendelian randomization analyzes to determine the potential association of systolic BP, diastolic BP, and pulse pressure with AF.
After Mendelian randomization, researchers found that each 1 mm Hg increase in systolic BP was associated with a 1.8% increased risk of AF (OR = 1.018; 95% CI: 1.012-1.024; P <.001>
In addition, the researchers demonstrated that for every 1 mm Hg increase in diastolic BP, there was a 2.6% increased risk of AF (OR = 1.026; 95% CI: 1.016-1.035; P P <.033>
According to the study, the relationship between AP and AF did not change when single-nucleotide polymorphisms associated with possible confounding factors such as coronary artery disease and obesity were excluded.
âSeveral different mechanisms may be involved in the pathogenesis of AF in hypertensive patients. Both hemodynamic and non-hemodynamic mechanisms are believed to promote complex changes in atrial structure, architecture, contraction, and electrophysiology with the potential to produce clinically relevant manifestations, âthe researchers wrote. âThe hemodynamic mechanisms involve the development of hypertensive cardiomyopathy characterized by increased left ventricular wall thickness, increased LV stiffness and impaired LV diastolic function. These processes can lead to increased left atrial stretch and pressure, with subsequent remodeling and dysfunction predisposing to AF.
“Among the non-hemodynamic mechanisms, there are histological changes in the atria such as proliferation of fibroblasts, alterations in the extracellular matrix and hypertrophy of myocytes which can alter the interconnections between muscle bundles and lead to electrophysiological remodeling,” wrote the researchers.