Pilot study to evaluate the predictive value of repeated (admission and 3 months) late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (CMR) in acute viral myocarditis (AVM).
Method
We prospectively included 49 patients hospitalized for an acute viral myocarditis diagnosed by CMR according to Lake Louise Criteria. We obtained written consent of all the patients. Patients were followed-up for one year after the index admission for adverse cardiac events that included myocarditis recurrence, persistent chest pain, dyspnea or persistent/resurgent sign of heart failure, documented sustained arrhythmias. Patients underwent a second LGE-CMR 3 months after the index admission. LGE was analyzed semi-quantitatively with the SQS score that has been validated in ischemic cardiomyopathies.
Results
The SQS calculated at the first CMR was poorly correlated with cardiac necrosis biomarkers such as troponin peak (r2=0.22) or CPK (r2=0.11), and inflammation biomarkers such as CRP (p=0,51). SQS1 was also not predictive of adverse cardiac events after the index admission. However, the variation of SQS score between the first and second CMR showed good pronostic value as estimated by ROC analysis (AUC, specificity 80%, sensitivity 62%). This analysis also showed that patients with a decrease in SQS<50% between the two CMR were at higher risk of adverse cardiac events.
Conclusion
The variation of LGE at admission of AVM and 3 months afterwards appears as a promising tool to identify patients with high risk of adverse envents during the year following a mild event of AVM.
