Cardiac features of MIS-C: MRI and Speckle-tracking data

Introduction In November 2019, the first case of SARS-CoV-2 infection was reported in China, the first European case was declared 2 months later in January 2020. While the pediatric population seemed to be less affected by SARS-CoV-2, an alert was launched in April 2020 following multiple cases of multisystem inflammatory syndrome in children (MIS-C), secondary to SARS-CoV-2 infection. The presentation shares clinical features with Kawasaki disease but involves almost systematically cardiac dysfunction. Cardiac involvement is central in MIS-C and represents the main cause of morbidity. Objective In this study, we therefore aimed to assess the myocardial damage in patients with MIS-C using MRI during the acute phase as well as left ventricular and atrial longitudinal strain during the acute phase and after recovery. Method We performed a single-center prospective cohort and case-control study. Between September 2020 and January 2022, we included 39 patients hospitalized for MIS-C in our center. We performed left ventricular and atrial longitudinal 2D strain analysis on admission and during follow-up;the analysis was compared to a matched control population. Patients above 4 years old with increased troponin underwent cardiac MRI. Results Of 22 patients who underwent cardiac MRI, 14 (64%) presented myocardial edema and 6 (27%) late gadolinium enhancement, the latter being associated with myopericarditis and impaired LVEF (P<0.001), older patients (P=0.027) and elevated ferritin (P=0.03). We found a decrease in left ventricular and atrial longitudinal strain on admission as compared to controls with a significant improvement at 1 month post-discharge (P<0.0001). The alteration in LV strain persisted beyond one month according the comparison with the control population (P=0.01). Conclusion Only little is known about the long-term follow-up and prognosis in MIS-C patients. Our study demonstrated the myocardial inflammation during the acute phase of MIS-C as well as the impaired LA and LV myocardial deformation that persists for at least several weeks after the acute phase. Thus, we believe MRI and LV/LA strain could help us individualize our MIS-C patients follow-up.

Effect of ASD closure on right ventricular function using 3D echocardiography

Introduction Atrial septal defect (ASD) is the most common adult congenital heart disease. The left-to-right shunt causes a right ventricular (RV) volume overload. Only little is known about RV remodeling after ASD closure. Objective We aimed to assess RV function using 2D, 3D echocardiography and 3D RV strain before and 1 month after ASD closure. Method We prospectively included in this monocentric study 9 patients with secundum ASD who underwent percutaneous closure between September 2019 and January 2020. 2D and 3D Echocardiography were performed in all patients before and 1-month after closure. While we initially planned to collect echocardiographic data 3- and 6-months after ASD closure, the COVID-19 pandemic made this impossible. All patients gave their informed consent to the study. Clinical and ultrasound data were collected and anonymized. 3D RV echocardiographic sequences were analyzed by semi-automatic software (Tomtec 4D RV Function, Unterschleissheim, Germany) and output meshes were post-processed to extract regional deformation. Results Patients' mean age was 31.0±12.3 years, 44.4% were female. Mean ASD diameter was 16.6±7.4mm. RV end diastolic diameter and right atrial (RA) area were significantly larger than normal values and decreased significantly after ASD closure (45.8±4.9 vs. 37.8±5.7mm;P=0.0009 and 21.4±4.2 vs. 16.3±2.7cm2;P=0.01, respectively). 3D RV volumes were significantly lower after ASD closure;respectively 156.3±61.7 vs. 82.9±17.40mL, P=0.02 for end diastolic volume and 59.4±19.3 vs. 32.6±9.2mL, P=0.01 for end systolic volume. RV function decreases after ASD closure as illustrated by TAPSE (23.3±6.0 vs. 29.1±4.2mm, P=0.03) as well as 3D RV strain with a significantly decreased in area strain, longitudinal strain as well as circumferential strain (respectively P=0.006, P=0.009 and P=0.02) (Fig. 1). Conclusion After percutaneous ASD closure, we demonstrate a decrease in RV function in all strain components using 3D strain. This decrease in RV strain probably illustrates the decrease in RV parietal stretch related to the normalization of RV loading conditions. 3D strain can be useful to assess the RV function evolution in response to different loading conditions.

Acute Heart Failure in Multisystem Inflammatory Syndrome in Children in the Context of Global SARS-CoV-2 Pandemic

Background: Cardiac injury and myocarditis have been described in adults with coronavirus disease 2019 (COVID-19). Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children is typically minimally symptomatic. We report a series of febrile pediatric patients with acute heart failure potentially associated with SARS-CoV-2 infection and the multisystem inflammatory syndrome in children as defined by the US Centers for Disease Control and Prevention. Methods: Over a 2-month period, contemporary with the SARS-CoV-2 pandemic in France and Switzerland, we retrospectively collected clinical, biological, therapeutic, and early outcomes data in children who were admitted to pediatric intensive care units in 14 centers for cardiogenic shock, left ventricular dysfunction, and severe inflammatory state. Results: Thirty-five children were identified and included in the study. Median age at admission was 10 years (range, 2-16 years). Comorbidities were present in 28%, including asthma and overweight. Gastrointestinal symptoms were prominent. Left ventricular ejection fraction was <30% in one-third;80% required inotropic support with 28% treated with extracorporeal membrane oxygenation. Inflammation markers were suggestive of cytokine storm (interleukin-6 median, 135 pg/mL) and macrophage activation (D-dimer median, 5284 ng/mL). Mean BNP (B-type natriuretic peptide) was elevated (5743 pg/mL). Thirty-one of 35 patients (88%) tested positive for SARS-CoV-2 infection by polymerase chain reaction of nasopharyngeal swab or serology. All patients received intravenous immunoglobulin, with adjunctive steroid therapy used in one-third. Left ventricular function was restored in the 25 of 35 of those discharged from the intensive care unit. No patient died, and all patients treated with extracorporeal membrane oxygenation were successfully weaned. Conclusions: Children may experience an acute cardiac decompensation caused by severe inflammatory state after SARS-CoV-2 infection (multisystem inflammatory syndrome in children). Treatment with immunoglobulin appears to be associated with recovery of left ventricular systolic function.