Acute myocarditis has a highly variable course ranging from complete recovery to end-stage dilated cardiomyopathy, and predictors of outcome are still largely unknown.
Aim of the study was to determine the potential value of short-term CMR for the prediction of adverse left ventricle remodeling.
From September 2016 to July 2018, 33 consecutive patients with biopsy-proven acute myocarditis underwent baseline CMR (11 ± 8 days after acute clinical presentation) and short-term CMR (65 ± 10 days from baseline MR). Lake-Louise criteria (LL), T1 and T2 mapping were evaluated at each time point, as well as their modification over time. MR parameters were correlated with left ventricle (LV) end-diastolic volume (EDV) and ejection fraction (EF) at short-term CMR.
The vast majority of patients (N = 18,54.5%) presented with infart-like clinical presentation (18,54.5%), followed by 9 (27.3%) with heart failure, 6 (18.2%) with sudden cardiac death/arrhythmia. At baseline CMR, LV volume was 135 ml with EF 53% with a significant elevation of both LL criteria (T2-ratio:2.8, Hyperemia.13%, LGE 6%) and mapping parameters (T1:1103.79, ECV: 31, T2: 53.95) without differences among clinical presentation (p>0.05). At short-term follow-up, a slight recovery of EF was experimented (56%), and all LL and mapping parameters significantly reduced (T2-ratio:2.3, Hyperemia.7%, LGE 4%, T1:1080, ECV: 28, T2: 51), without differences among clinical presentations. Among all parameters analyzed only short-term recovery of T1 mapping was associated to improved LV volume and function (EDV R=0.884, p<0,001, FE%; R= 0,757, p<0,001).
Short-term T1 recovery is significantly associated to favorable left ventricle remodeling.