Feature tracking cardiovascular magnetic resonance reveals recovery of atrial function after acute myocarditis.

Follow-up after acute myocarditis is important to detect persisting myocardial dysfunction. However, recovery of atrial function has not been evaluated after acute myocarditis so far. Thirty-five patients with strictly defined acute myocarditis underwent cardiovascular magnetic resonance (CMR, 1.5 T) in the acute stage at baseline (BL) and at 3 months follow-up (FU). The study population included 13 patients with biopsy-proven "cardiomyopathy-like" myocarditis (CLM) and 22 patients with "infarct-like" (ILM) clinical presentation. CMR feature tracking (FT) was performed on conventional cine SSFP sequences. Median LA-GLS increased from 33.2 (14.5; 39.2) at BL to 37.0% (25.2; 44.1, P = 0.0018) at FU in the entire study population. Median LA-GLS also increased from 36.7 (26.5; 42.3) at BL to 41.3% (34.5; 44.8, P = 0.0262) at FU in the ILM subgroup and from 11.3 (6.4; 21.1) at BL to 21.4% (14.2; 30.7, P = 0.0186) at FU in the CLM subgroup. Median RA-GLS significantly increased from BL with 30.8 (22.5; 37.0) to FU with 33.7% (26.8; 45.4, P = 0.0027) in the entire study population. Median RA-GLS also significantly increased from 32.7 (25.8; 41.0) at BL to 35.8% (27.7; 48.0, P = 0.0495) at FU in the ILM subgroup and from 22.8 (13.1; 33.9) at BL to 31.0% (26.0; 40.8, P = 0.0266) at FU in the CLM subgroup. Our findings demonstrate recovery of LA and RA function by CMR-FT strain analyses in patients after acute myocarditis independent from clinical presentation. Monitoring of atrial strain could be an important tool for an individual assessment of healing after acute myocarditis.

Tissue characterization by T1 and T2 mapping cardiovascular magnetic resonance imaging to monitor myocardial inflammation in healing myocarditis.

AIMS: Monitoring disease activity in myocarditis is important for tailored therapeutic strategies. This study evaluated the ability of T1 and T2 mapping cardiovascular magnetic resonance (CMR) to monitor the course of myocardial inflammation in healing myocarditis. METHODS AND RESULTS: Forty-eight patients with strictly defined acute myocarditis underwent CMR at 1.5 T in the acute stage, at 3-months (n = 39), and at 12-months follow-up (FU) (n = 21). Normal values were obtained in a control group of 27 healthy subjects. The CMR protocol included standard ('Lake-Louise') sequences as well as T1 (modified Look-Locker inversion recovery sequence, MOLLI) and T2 (gradient- and spin-echo sequence, GraSE) mapping. T1, T2, and extracellular volume (ECV) maps were generated using an OsiriX plug-in. Native myocardial T1, T2, and ECV values were increased in the acute stage, but declined with healing of myocarditis. The performances of global native T1 and T2 to differentiate acute from healed myocarditis stages were significantly better compared with all other global CMR parameters with AUCs of 0.85 (95% CI, 0.76-0.94) and 0.83 (95% CI, 0.73-0.93). Furthermore, regional native T1 and T2 in myocarditis lesions provided AUCs of 0.97 (95% CI, 0.93-1.02) and 0.93 (95% CI, 0.85-1.01), which were significantly superior to any other global or regional CMR parameter. CONCLUSION: Healing of myocarditis can be monitored by native myocardial T1 and T2 measurements without the need for contrast media. Both native myocardial T1 and T2 provide an excellent performance for assessing the stage of myocarditis by CMR.