Plasma SFRP2 hypermethylation as a diagnostic biomarker for dilated cardiomyopathy detected by methylation-specific PCR.

Objective: To investigate the clinical utility of plasma Secreted Frizzled-Related Protein 2 (SFRP2) gene hypermethylation as a non-invasive epigenetic biomarker for diagnosing Dilated cardiomyopathy (DCM) and stratifying cardiac function.

Methods: A retrospective cohort of 482 participants (241 DCM patients and 241 healthy controls) was analyzed. DCM patients were further stratified by New York Heart Association (NYHA) class into better cardiac function (BCF; NYHA I-II) and poor cardiac function (PCF; NYHA III-IV) groups. Methylation-specific polymerase chain reaction (MSP) was used to assess SFRP2 methylation levels. Statistical analyses evaluated its diagnostic value, including receiver operating characteristic (ROC) curve analysis to determine sensitivity and specificity.

Results: Plasma SFRP2 methylation levels were significantly higher in DCM patients than in controls (P < 0.001). ROC analysis revealed an area under the curve (AUC) of 0.942, indicating excellent diagnostic performance. Among DCM patients, the PCF group exhibited significantly higher SFRP2 methylation levels compared to the BCF group (P < 0.001). Additionally, SFRP2 methylation showed a strong positive correlation with worsening cardiac function (r = 0.786, P < 0.001).

Conclusion: Elevated plasma SFRP2 methylation levels in DCM patients, particularly those with poor cardiac function, demonstrate its high diagnostic accuracy and potential to reflect disease severity, supporting its use as a non-invasive clinical biomarker for DCM diagnosis and risk stratification.