(C29) Critically Appraised Topic: What is the Clinical Potential for MicroRNAs as Cardiac Biomarkers in Dogs?

Abstract: Background- Cardiac disease is common in dogs but diagnosis and monitoring require specialist imaging. Cardiac biomarkers can provide key information in the primary care setting. MicroRNAs are novel biomarkers with application to cardiac disease. Objectives/ Hypothesis- Does measurement of microRNA biomarkers show potential for diagnosis of myocardial disease with respect to 1) presence and 2) severity when compared with echocardiography? Animals- N/A Methods- This was a critically appraised topic using PICO methodology. A search strategy was developed (PUBMED; January 2007-December 2024). Studies were included describing microRNAs associated with naturally occurring cardiac disease in dogs. Exclusion criteria were defined (no gold standard comparison, secondary source, case report). Manuscripts were reviewed and data extracted (condition, population, methods and results). Study quality was assessed and recommendations made (GRADE). Studies were sub-categorised by pathology. Results- From 76 studies retrieved, 61 were excluded (22 not relevant, 35 experimental, 4 review articles). Fifteen met the inclusion criteria (14 case-control; one longitudinal case series). Six studies evaluated ACVIM staged myxomatous mitral valve disease (MMVD) with differences in microRNA expression between A and B and B and C/D disease. Heterogeneity in microRNAs prohibited evidence synthesis. Remaining studies demonstrated the application of microRNA profiling to a range of cardiac pathologies (unstaged MMVD, pulmonic stenosis, dilated cardiomyopathy). Conclusions and clinical importance- There is strong evidence in favour of the potential for microRNAs being a useful future addition to canine cardiac diagnostics particularly for MMVD. Further work determining microRNA panels with optimal discriminatory power is needed.