Cardiac MR With Late Gadolinium Enhancement in Acute Myocarditis With Preserved Systolic Function: ITAMY Study

The prognostic role of cardiac magnetic resonance (CMR) and late gadolinium enhancement (LGE) has not been clarified in acute myocarditis (AM) with preserved left ventricular (LV) ejection fraction (EF).

This study sought to evaluate the role of CMR and LGE in the prognosis of AM with preserved LVEF.

This study analyzed data from ITAMY (ITalian multicenter study on Acute MYocarditis) and evaluated CMR results from 386 patients (299 male; mean age 35 ± 15 years) with AM and preserved LVEF. Clinical follow-up was performed for a median of 1,572 days. A clinical combined endpoint of cardiac death, appropriate implantable cardioverter-defibrillator firing, resuscitated cardiac arrest, and hospitalization for heart failure was used.

Among the 374 patients with suitable images, LGE involved the subepicardial layer inferior and lateral wall in 154 patients (41%; IL group), the midwall layer of the anteroseptal wall in 135 patients (36%; AS [anteroseptal] group), and other segments in 59 patients (16%; other-LGE group), and it was absent in 26 patients (no-LGE group). The AS group had a greater extent of LGE and a higher LV end-diastolic volume index than other groups, but levels of inflammatory markers were lower than in the other groups. Kaplan-Meier curve analysis indicated that the AS group had a worse prognosis than the other groups (p < 0.0001). Finally, in multivariable analysis, AS LGE was the best independent CMR predictor of the combined endpoint (odds ratio: 2.73; 95% confidence interval: 1.2 to 5.9; p = 0.01).

In patients with AM and preserved LVEF, LGE in the midwall layer of the AS myocardial segment is associated with a worse prognosis than other patterns of presentation.