The risk for major valvular heart disease is greater among those with lifetime elevated systolic blood pressure, according to a study recently published in JAMA Cardiology. Researchers suggested using blood pressure–lowering medications to curtail this risk among vulnerable individuals.
In this mendelian randomization study, researchers observed 329,237 individuals (53.99% women) between the ages of 40 and 96 (mean age 56.93±7.99 years) at baseline, all of whom had blood pressure measurements and genetic data sourced from the UK Biobank. This individual data was used to evaluate systolic blood pressure exposure, as well as incident aortic regurgitation, aortic stenosis, and/or mitral regurgitation. Recruitment took place between 2006 and 2010.
Researchers built genetic instruments for systolic blood pressure through single-nucleotide polymorphisms with a linkage disequilibrium of r² at less than 0.1 that were correlated with systolic blood pressure (minor allele frequency >0.01). In total, 130 single-nucleotide polymorphisms were selected. A sensitivity analysis was performed to explore whether the potential association between high systolic blood pressure and valvular heart disease was related to coronary heart disease and heart failure.
Valvular heart disease was present among 1.08% (n=3570) of the study population, with 1491 having a diagnosis of aortic stenosis, 634 of aortic regurgitation, and 1736 of mitral regurgitation.
The risk for aortic stenosis was found to increase by a factor of 3.26 (95% CI, 1.50-7.10) with each genetically related 20 mm Hg increase in systolic blood pressure, as was the risk for mitral regurgitation (odds ratio [OR], 2.19; 95% CI, 1.07-4.47) and the risk for aortic regurgitation (OR, 2.59; 95% CI, 0.75-8.92).
The type of valvular heart disease did not affect these findings (P =.90), and sensitivity analyses supported these findings.
Limitations to this study included a low occurrence of certain valvular heart disease types, a lack of statistical power in detecting certain mediating associations, potential misclassification due to a lack of echocardiographic data, and the exclusive recruitment of individuals of European descent.
Study researchers concluded that “lifetime exposure to elevated systolic [blood pressure] may be associated with an increased risk of major [valvular heart disease]. Our mendelian randomization study is less prone to confounding and reverse causation and thus suggests that [blood pressure]-lowering treatment may be a useful strategy for [the] prevention of [valvular heart disease].”
Nazarzadeh M, Pinho-Gomes AC, Smith Byrne K, et al. Systolic blood pressure and risk of valvular heart disease: a mendelian randomization study [published online July 10, 2019]. JAMA Cardiol. doi:10.1001/jamacardio.2019.2202