Background:

Fulminant myocarditis is a rare form of acute myocarditis characterized by severe hemodynamic compromise requiring inotropes and/or timely mechanical circulatory support.¹ To date, however there are only few reports with relative small sample focusing on the traditional Cardiac MR imaging characteristics in fulminant myocarditis.² Furthermore, the clinical value of novel mapping techniques and strain measures to assess myocardial inflammation has not been fully explored. Therefore, the aim of this study was to evaluate whether mapping and strain cardiac MRI have the ability to assess myocardial inflammation in fulminant myocarditis, and to which degree the strain metrics correlate with quantitative parameters of myocardial inflammation.

Methods:

Fifty-eight patients (29 patients with fulminant myocarditis, mean age ± standard deviation, 37 years ± 16 [range:15–72years]; 29 patients with non-fulminant acute myocarditis, mean age, 29 years ± 14 [range:14–62years]) with clinical suspected myocarditis were prospectively recruited. All subjects underwent cardiac MRI at 3T(MAGNETOM Skyra，Siemens Healthcare，Erlangen，Germany) , and the scanning sequences included cine, black blood T2 weighted imaging, T1 mapping, T2 mapping and late gadolinium enhancement (LGE). Myocardial strain analysis was applied on standard cine images of long and short axis views.

Results:

The myocardial edema rate（2.6±0.7 vs 1.6±0.2, P < 0.001）and LGE mass (16.5 [11.7,41.7] vs 6.9 [2.2,15.8], p < 0.001)were significantly increased in FM patients when compared to the NFAM group. LGE in FM group predominantly located in septal wall (Fig.1), and 38% of the patients showed a diffuse LGE pattern. Native T1, extracellular volume(ECV) and T2 values in FM group were significantly elevated than those with NFAM，while global peak radial（RS）, circumferential（CS） and longitudinal strain（LS）values were significantly reduced(all p<0.001). CS showed the strongest correlations with ECV（r=0.724, p<0.001) (Fig. 2).

Discussion and conclusions:

In this study, the preliminary data from our study demonstrate FM patients showed different LGE patterns, increased edema(high T1/T2 value) and decreased strain measurements compared with NFAM. These imaging findings were associated with severe clinical manifestations in FM. Interestingly, global CS was the only strain indices that showed a significant correlation with all quantitative Cardiac MRI parameters of myocardial edema in FM patients. Especially, the strongest correlation was found with ECV. The possible reasons may be explained by the extensive inflammatory myocardial injuries in FM, resulting in a greater expansion of myocardial ECV. Further multi-center studies are needed to assess the prognosis value of this imaging findings in fulminant myocarditis.

Acknowledgements

No acknowledgement found.