Baseline C-reactive protein as a predictor of non-ischemic LGE in myocarditis

Abstract Background Identifying reliable early indicators of myocardial injury in myocarditis is a pressing concern in cardiology. Despite their established role in detecting myocardial necrosis, traditional markers like high-sensitivity cardiac troponin (hs-cTn) may not fully capture the extent of myocardial damage identified by non-ischemic late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) Purpose To identify early admission biomarkers associated with non-ischemic LGE in patients with myocarditis, offering the potential for improved risk stratification and therapeutic targeting. Methods In this retrospective study, we analyzed 59 myocarditis patients admitted to a high-volume medical center from 2017 to 2023, who underwent CMR to evaluate LGE. 41 patients (69.5%) exhibited non-ischemic LGE and 18 (30.5%) did not. We assessed baseline laboratory and echocardiographic parameters, employing Pearson correlation, logistic regression, and ROC curve analyses to elucidate the potential association of baseline biomarkers with non-ischemic LGE, while also discerning subepicardial from midwall patterns. Results Baseline C-reactive Protein (CRP) levels were significantly correlated with non-ischemic LGE (Pearson's r=0.301, p<0.05). Logistic regression analysis substantiated CRP as a predictor of non-ischemic LGE (OR=1.41, p<0.05), corroborated by a multivariate approach even after accounting for age and sex (OR=1.33; p<0.05). Among non-ischemic patterns, subepicardial LGE exhibited the strongest correlation with CRP (Pearson's r=0.321, p<0.05). In contrast, hs-cTn levels showed no significant association with non-ischemic LGE. The ROC analysis revealed that while both CRP and hs-cTn provide valid predictive values for non-ischemic LGE, with AUCs of 0.7333 and 0.6898 respectively, CRP demonstrated a higher discriminative performance, indicating that CRP may offer a more reliable assessment in this clinical context. Additionally, diabetic status emerged as the most significant condition associated with increased CRP levels, with diabetic patients presenting a substantial elevation in baseline CRP compared to non-diabetic patients (8.75 mg/dl vs 3.21 mg/dl; p<0.05). Conclusion CRP appears as a key early biomarker for non-ischemic LGE in myocarditis, with its predictive value being particularly evident in the subepicardial pattern and notably more pronounced among diabetic patients who demonstrate an increased inflammatory burden. These findings suggest a critical role for CRP in risk stratification right from the point of hospital admission and underline the potential for tailored therapeutic approaches that warrant further investigations. Figure 1: ROC curves comparison for CRP and hs-cTn in predicting non-ischemic LGE in myocarditis patients. Figure 2: Patients with diabetes (DM) exhibit significantly higher CRP levels (mean 8.75 mg/dl, SE = 5.54 mg/dl) than those without DM (mean 3.21 mg/dl, SE = 0.49 mg/dl).ROC curves comparisonCPR in patients with and without DM