Regional extracellular volume within late gadolinium enhancement-positive myocardium to differentiate cardiac sarcoidosis from myocarditis of other etiology: a cardiovascular magnetic resonance study.

BACKGROUND: Cardiovascular magnetic resonance (CMR) plays a pivotal role in diagnosing myocardial inflammation. In addition to late gadolinium enhancement (LGE), native T1 and T2 mapping as well as extracellular volume (ECV) are essential tools for tissue characterization. However, the differentiation of cardiac sarcoidosis (CS) from myocarditis of other etiology can be challenging. Positron-emission tomography-computed tomography (PET-CT) regularly shows the highest Fluordesoxyglucose (FDG) uptake in LGE positive regions. It was therefore the aim of this study to investigate, whether native T1, T2, and ECV measurements within LGE regions can improve the differentiation of CS and myocarditis compared with using global native T1, T2, and ECV values alone. METHODS: PET/CT confirmed CS patients and myocarditis patients (both acute and chronic) from a prospective registry were compared with respect to regional native T1, T2, and ECV. Acute and chronic myocarditis were defined based on the 2013 European Society of Cardiology position paper on myocarditis. All parametric measures and ECV were acquired in standard fashion on three short-axis slices according to the ConSept study for global values and within PET-CT positive regions of LGE. RESULTS: Between 2017 and 2020, 33 patients with CS and 73 chronic and 35 acute myocarditis patients were identified. The mean ECV (± SD) in LGE regions of CS patients was higher than in myocarditis patients (CS vs. acute and chronic, respectively: 0.65 ± 0.12 vs. 0.45 ± 0.13 and 0.47 ± 0.1; p < 0.001). Acute and chronic myocarditis patients had higher global native T1 values (1157 ± 54 ms vs. 1196 ± 63 ms vs. 1215 ± 74 ms; p = 0.001). There was no difference in global T2 and ECV values between CS and acute or chronic myocarditis patients. CONCLUSION: This is the first study to show that the calculation of regional ECV within LGE-positive regions may help to differentiate CS from myocarditis. Further studies are warranted to corroborate these findings.

Minimally invasive left atrial appendage (LAA) clip insertion after challenging LAA occluder implantation to minimize the risk of stroke.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, requiring lifelong anticoagulation or interventional, transseptal left atrial appendage (LAA) occluder implantation to minimize stroke risk. Incomplete LAA closure post implantation is a frequent observation. Incomplete LAA occlusion after transseptal occluder implantation necessitates anticoagulation in cases of persistent AF to minimze risk of embolism and/or apoplexy. Patients with contraindications to lifelong anticoagulation therapy are challenging to treat and alternative options are needed. We present a case of a patient with persistent AF who underwent frustraneous LAA occluder implantation. The patient's anatomy necessitated surgical closure of the LAA, which was accomplished with an LAA clip 4 weeks after implantation. The patient was discharged in excellent clinical status 5 days after the surgery. No further complications were observed within the following year.