Comparison of serum microRNA in healthy horses and horses with moderate to severe mitral valve regurgitation using a commercially available canine cardiac panel.
Authors: Calewaert Amber, Palarea-Albaladejo Javier, Coultous Robert, Capewell Paul, Hanks Eve, Decloedt Annelies, van Loon Gunther
Journal: Equine veterinary journal
Summary
# Editorial Summary Mitral valve regurgitation is a common cardiac condition in horses, yet non-invasive biomarkers for diagnosis remain limited; this research explored whether microRNA (miRNA) — molecular markers already validated in human and canine cardiac disease — could similarly identify affected equine patients. The authors analysed serum samples from 77 horses with moderate to severe mitral regurgitation and 77 healthy controls using a commercially available cardiac miRNA panel originally developed for canine use, examining whether expression profiles differed between groups. Despite strong evolutionary conservation of miRNA sequences across species, the canine panel demonstrated poor discriminatory power in horses, achieving only 58% sensitivity and 57% specificity — essentially no better than chance for clinical decision-making. Whilst the negative result is disappointing for practitioners seeking improved screening tools, it highlights important species-specific differences in cardiac biomarker expression and suggests that equine-specific miRNA panels, calibrated to the distinct pathophysiology of equine mitral regurgitation, may be necessary rather than cross-species adaptation. Further investigation using equine-optimised assays is warranted before clinicians should expect blood-based miRNA testing to meaningfully assist in diagnosing or monitoring valvular disease in horses.
Read the full abstract on PubMed
Practical Takeaways
- •Do not rely on commercially available canine cardiac miRNA panels for diagnosing mitral valve regurgitation in horses—they lack sufficient diagnostic accuracy
- •Current serum miRNA testing cannot yet replace or supplement echocardiographic examination for cardiac disease screening in horses
- •Future development of equine-specific miRNA panels may eventually offer a non-invasive blood-based cardiac biomarker, but this technology is not yet clinically validated
Key Findings
- •A commercially available canine cardiac miRNA panel showed low discriminatory power in horses, with sensitivity of 0.58 (95% CI: 0.47–0.69) and specificity of 0.57 (95% CI: 0.46–0.68) for detecting mitral valve regurgitation
- •Despite strong conservation of miRNA sequences across species, a canine-derived assay failed to serve as an effective biomarker for equine mitral valve regurgitation
- •An equine-specific miRNA panel may be needed to develop a clinically useful cardiac biomarker for horses