Case report: acute myocarditis in two patients with coronary artery disease presenting with chest pain-thinking outside the box.

Background: In a subset of patients, acute myocarditis (AM) may mimic acute myocardial infarction, with a similar clinical presentation characterized by chest pain, electrocardiogram (ECG) changes consistent with acute coronary syndromes (ACS), and serum markers increment. Case summary: We present two cases of infarct-like myocarditis in patients with known coronary artery disease (CAD), in which the discrepancy between transthoracic echocardiogram findings, ECG, and angiography prompted us to look beyond the simplest diagnosis. In these cases, making a prompt and correct diagnosis is pivotal to address adequate therapy and establish a correct prognosis. Discussion: The right diagnosis can avoid unnecessary coronary revascularizations and subsequent antiplatelet therapy that may be associated with an increased haemorrhagic risk. Moreover, it allows setting up guideline-directed therapy for myocarditis, proper follow-up, as well as recommending abstention from physical activity.

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.

Clinical and magnetic resonance evolution of "infarct-like" myocarditis.

AIMS: To analyse the clinical and magnetic resonance evolution of myocarditis in patients with an "infarct-like" presentation pattern. METHODS: The study is a retrospective analysis of 52 patients with clinical diagnosis of "infarct-like" myocarditis confirmed by CMR as acute myocarditis according to Lake Louise criteria and 6 months follow-up. The CMR protocol included T2-weighted (oedema), early (hyperaemia) and late (fibrosis/necrosis) gadolinium enhancement sequences, according to Lake Louise criteria. Clinical and radiological follow-up by CMR was performed after a median time interval of 6 months (interquartile range 5-8). Quantitative outcomes were checked for normality and compared with the non-parametric Wilcoxon's test for matched data. RESULTS: At the clinical follow-up all patients were free of symptoms and reported no cardiac complications. The CMR follow-up evidenced a significant increase of the ejection fraction (from 53 ± 6 to 55 ± 4%, p = 0.03), a decrease of the ventricular mass [from 67.0 (58.8-79.0) to 61.0 (54.0-67.0), p < 0.0001] without significant modification of the cardiac volume index (p = 0.26). No patient had residual oedema or capillary leakage: the T2 ratio decreased from 3.94 (3.00-4.86) to 0.98 (0.75-1.17) with p < 0.0001 and the Early gadolinium enhancement (EGE) ratio from 5.7 (4.8-6.5) to 2.9 (2.4-3.2) with p < 0.0001. Late gadolinium enhancement (LGE) persisted over the course of the follow-up in 48/52 patients, but with a significant reduction in every patient (LGE % from 34.3 ± 9.1 to 19.4 ± 6.6%; p < 0.0001). CONCLUSION: Patients diagnosed with "infarct-like" myocarditis, according to both clinical and CMR examinations may look forward to a positive evolution with a good prognosis.