Circulating Levels of MicroRNAs in Hypertrophic Cardiomyopathy: The Relationship With Left Ventricular Hypertrophy, Left Atrial Dilatation and Ventricular Depolarisation-Repolarisation Parameters

Circulating microRNAs in predicting fibrosis in hypertrophic cardiomyopathy: A systematic review

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is characterized by left ventricular hypertrophy and interstitial fibrosis, which contribute to adverse outcomes such as heart failure and sudden cardiac death. While cardiac magnetic resonance (CMR) imaging is commonly used to detect myocardial fibrosis, circulating microRNAs (miRNAs) have emerged as promising noninvasive biomarkers for this condition due to their stability in blood plasma and resistance to pH and temperature variance.

AIM

To explore the role of specific circulating miRNAs in identifying myocardial fibrosis in patients with HCM.

METHODS

Using PubMed/MEDLINE and Google Scholar, we reviewed studies from 2014 to 2024 examining the link between circulating miRNAs and myocardial fibrosis in HCM. We included studies measuring miRNA expression in blood samples from HCM patients and assessing fibrosis via imaging, mostly CMR. Data extraction concentrated on the population, methodology, and findings related to the correlation between miRNA levels and fibrosis.

RESULTS

Seven studies involving 365 HCM patients with a mean age of 49.37 ± 10.5 years, 116 (31.78%) females, and one animal study identified miR-21, miR-29a, miR-133, miR-4454, and miR-221 as frequently dysregulated markers associated with fibrosis. Elevated levels of miR-21 and miR-29a correlated with more extensive fibrosis, as assessed by late gadolinium enhancement in CMR imaging, with miR-29a consistently linked to both fibrosis and hypertrophy across the studies.

CONCLUSION

Circulating miRNAs, particularly miR-21, miR-29a, and miR-221, show significant potential as biomarkers for myocardial fibrosis in HCM. Further research should validate these findings and investigate the clinical application of miRNA-based diagnostics in HCM.

Circulating MicroRNAs Identify Early Phenotypic Changes in Sarcomeric Hypertrophic Cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy. Pathogenic germline variation in genes encoding the sarcomere is the predominant cause of disease. However diagnostic features, including unexplained left ventricular hypertrophy, typically do not develop until late adolescence or after. The early stages of disease pathogenesis and the mechanisms underlying the transition to a clinically overt phenotype are not well understood. In this study, we investigated if circulating microRNAs (miRNAs) could stratify disease stage in sarcomeric HCM.

METHODS

We performed arrays for 381 miRNAs using serum from HCM sarcomere variant carriers with and without a diagnosis of HCM and healthy controls. To identify differentially expressed circulating miRNAs between groups, multiple approaches were used including random forest, Wilcoxon rank sum test, and logistic regression. The abundance of all miRNAs was normalized to miRNA-320.

RESULTS

Of 57 sarcomere variant carriers, 25 had clinical HCM and 32 had subclinical HCM with normal left ventricular wall thickness (21 with early phenotypic manifestations and 11 with no discernible phenotypic manifestations). Circulating miRNA profile differentiated healthy controls from sarcomere variant carriers with subclinical and clinical disease. Additionally, circulating miRNAs differentiated clinical HCM from subclinical HCM without early phenotypic changes; and subclinical HCM with and without early phenotypic changes. Circulating miRNA profiles did not differentiate clinical HCM from subclinical HCM with early phenotypic changes, suggesting biologic similarity between these groups.

CONCLUSIONS

Circulating miRNAs may augment the clinical stratification of HCM and improve understanding of the transition from health to disease in sarcomere gene variant carriers.

A systematic review of miRNAs as biomarkers for chemotherapy-induced cardiotoxicity in breast cancer patients reveals potentially clinically informative panels as well as key challenges in miRNA research

Breast cancer patients are at a particularly high risk of cardiotoxicity from chemotherapy having a detrimental effect on quality-of-life parameters and increasing the risk of mortality. Prognostic biomarkers would allow the management of therapies to mitigate the risks of cardiotoxicity in vulnerable patients and a key potential candidate for such biomarkers are microRNAs (miRNA). miRNAs are post-transcriptional regulators of gene expression which can also be released into the circulatory system and have been associated with the progression of many chronic diseases including many types of cancer. In this review, the evidence for the potential application of miRNAs as biomarkers for chemotherapy-induced cardiotoxicity (CIC) in breast cancer patientsis evaluated and a simple meta-analysis is performed to confirm the replication status of each reported miRNA. Further selection of miRNAs is performed by reviewing the reported associations of each miRNA with other cardiovascular conditions. Based on this research, the most representative panels targeting specific chemotherapy agents and treatment regimens are suggested, that contain several informative miRNAs, including both general markers of cardiac damage as well as those for the specific cancer treatments.