Circulating microRNA Profiling Needs Further Refinement Before Clinical Use in Patients With Aortic Stenosis

BACKGROUND: Aortic stenosis (AS) is a progressive condition leading to heart failure and death without treatment. No medical therapy currently exists for AS, and a major management challenge is deciding on the correct timing of aortic valve replacement. MicroRNAs (miRNAs) are short noncoding RNAs that are stable in the circulation. We wished to use miRNAs as biomarkers of disease in AS. METHODS AND RESULTS: We performed microarray-based whole miRNome profiling of 24 participants with AS and 27 control participants. After adjustment for age and multiple testing, we identified 4 miRNAs significantly different between groups. These findings were then examined using quantitative polymerase chain reaction in a larger validation cohort of 101 controls and 94 participants with AS, stratified in a prespecified analysis by presence of coexisting coronary artery disease (CAD). We obtained mixed results for miR-22-3p, miR-24-3p, miR-382-5p, and miR-451a in the validation cohort, with differing associations according to CAD status. miR-21-5p was increased in AS patients without CAD, but there was no difference between groups with CAD. CONCLUSION: Despite holding great promise, circulating miRNA profiling requires further refinement before translation into clinical use as a biomarker in aortic stenosis.