Background: Acute myocardial infarction (AMI) remains a leading cause of mortality and morbidity worldwide. Early identification of reliable biomarkers is crucial for improving diagnostic accuracy and prognostic assessment in AMI patients. Circular RNAs (circRNAs) have emerged as novel regulators in cardiovascular diseases and may serve as promising biomarkers. Our study aimed to evaluate the expression level of Circular RNA 0049271 (Circ_0049271) and its potential role in diagnosing and predicting acute ST-segment elevation myocardial infarction (STEMI).

Methods: In this prospective cohort study, 188 STEMI patients and 86 healthy controls were enrolled between July 2020 and April 2024. Clinical information, including medical history, biochemical parameters, and cardiac function scores, was collected from all participants. Circ_0049271 expression was quantified using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Spearman's correlation analysis was conducted to assess the association between Circ_0049271 and cardiac troponin I (cTnI) levels. The diagnostic performance of Circ_0049271 for STEMI was evaluated using the receiver operating characteristic (ROC) curve. Additionally, logistic regression was applied to identify associations between various risk factors and STEMI. The Kaplan-Meier method estimated postoperative survival rates, and the Cox proportional hazards regression model analyzed the association between risk factors and the occurrence of major adverse cardiovascular events (MACE) after surgery.

Results: Circ_0049271 expression was significantly elevated in STEMI patients compared to healthy controls and was positively correlated with the myocardial injury marker cTnI (r = 0.65, p < 0.001). ROC curve analysis demonstrated high diagnostic accuracy for Circ_0049271 [area under the ROC curve (AUC) = 0.9099, 95% confidence interval (CI): 0.8618–0.9579]. Logistic regression identified body mass index, diastolic blood pressure, history of hypertension, low-density lipoprotein, high-sensitivity C-reactive protein, and Circ_0049271 as risk factors for STEMI. Furthermore, Kaplan-Meier analysis and the Cox proportional hazards regression model revealed that high Circ_0049271 expression was associated with an increased risk of MACE after percutaneous coronary intervention (PCI), indicating it as an independent risk factor for the occurrence of MACE.

Conclusion: Elevated Circ_0049271 levels in STEMI patients suggest its potential as a biomarker for the diagnosis and prognosis of STEMI. These findings provide valuable insights into the molecular mechanisms of AMI and suggest that Circ_0049271 could aid in developing more effective diagnostic and prognostic assessment tools.