Left atrial stiffness and strain are novel indices of left ventricular diastolic function in children: validation followed by application in multisystem inflammatory syndrome in children due to COVID-19.

AIMS: We hypothesized left atrial (LA) stiffness may serve as a surrogate marker in children to differentiate elevated pulmonary capillary wedge pressure (PCWP) from normal and help detect diastolic dysfunction in myocardial injury due to multisystem inflammatory syndrome in children (MIS-C). METHODS AND RESULTS: We validated LA stiffness in 76 patients (median age 10.5 years), 33 had normal PCWP (<12 mmHg) and 43 had elevated PCWP (≥12 mmHg). LA stiffness was applied to 42 MIS-C patients [28 with myocardial injury (+) and 14 without myocardial injury (-)], defined by serum biomarkers. The validation group consisted of a group with and without cardiomyopathies, whose PCWP values ranged from normal to severely elevated. Peak LA strain was measured by speckle-tracking and E/e' from apical four chamber views. Noninvasive LA stiffness was calculated as: LAStiffness=E/e'LAPeakStrain (%-1). Patients with elevated PCWP showed significantly elevated LA stiffness [median 0.71%-1 vs. 0.17%-1, P < 0.001]. Elevated PCWP group showed significantly decreased LA strain (median: 15.0% vs. 38.2%, P < 0.001). Receiver operator characteristic (ROC) curve for LA stiffness yielded an area under the curve (AUC) of 0.88 and cutoff value of 0.27%-1. In MIS-C group, ROC curve yielded an AUC of 0.79 and cutoff value of 0.29%-1 for identifying myocardial injury. CONCLUSION: In children with elevated PCWP, LA stiffness was significantly increased. When applied to children with MIS-C, LA stiffness classified myocardial injury accurately. LA stiffness and strain may serve as noninvasive markers of diastolic function in the pediatric population.

Outcomes of pediatric lupus care delivery in an electronic health record-based pediatric lupus registry

618 Table 2Factors associated with timely outpatient rheumatology follow-up RR 95% CI p-value Month of fol ow-up 0.99 [0.98 - 1.00] 0.09 Post-MOC 1.09 [0.93 - 1.28] 0.29 Age at visit 0.97 [0.94 – 1.00] 0.09 Male sex 0.92 [0.73 - 1.16] 0.49 Race/ethnicity  Reference: Non-Hispanic White -  Asian alone or in combination 1.20 [0.91 - 1.58] 0.19  Black alone or in combination 1.22 [0.92 - 1.62] 0.17  Hispanic White/Other 1.51 [1.15 - 1.99] 0.00  Non-Hispanic Other race 0.54 [0.28 - 1.02] 0.06 Social Vulnerability Index  Lowest  Medium Low 1.00 [0.75 - 1.33] 0.98  Medium High 0.94 [0.71 - 1.25] 0.68  Highest 1.03 [0.82 - 1.29] 0.82 Within 6 months of diagnosis at last visit 1.26 [1.05 - 1.53] 0.02 Prednisone use at last visit 1.17 [0.93 - 1.46] 0.17 SLEDAI score at last visit 1.02 [1.01 - 1.04] 0.01 Any DMARD use at last visit 1.52 [1.04 - 2.24] 0.03 History of synovitis 0.85 [0.70 - 1.05] 0.13 History of lupus nephritis 1.13 [0.95 - 1.35] 0.17 Estimates from modified robust Poisson models with subject-level random effects

Longitudinal Assessment of Cardiac Outcomes of Multisystem Inflammatory Syndrome in Children Associated With COVID-19 Infections.

Background In multisystem inflammatory syndrome in children, there is paucity of longitudinal data on cardiac outcomes. We analyzed cardiac outcomes 3 to 4 months after initial presentation using echocardiography and cardiac magnetic resonance imaging. Methods and Results We included 60 controls and 60 cases of multisystem inflammatory syndrome in children. Conventional echocardiograms and deformation parameters were analyzed at 4 time points: (1) acute phase (n=60), (2) subacute phase (n=50; median, 3 days after initial echocardiography), (3) 1-month follow-up (n=39; median, 22 days), and (4) 3- to 4-month follow-up (n=25; median, 91 days). Fourteen consecutive cardiac magnetic resonance imaging studies were reviewed for myocardial edema or fibrosis during subacute (n=5) and follow-up (n=9) stages. In acute phase, myocardial injury was defined as troponin-I level ≥0.09 ng/mL (>3 times normal) or brain-type natriuretic peptide >800 pg/mL. All deformation parameters, including left ventricular global longitudinal strain, peak left atrial strain, longitudinal early diastolic strain rate, and right ventricular free wall strain, recovered quickly within the first week, followed by continued improvement and complete normalization by 3 months. Median time to normalization of both global longitudinal strain and left atrial strain was 6 days (95% CI, 3-9 days). Myocardial injury at presentation (70% of multisystem inflammatory syndrome in children cases) did not affect short-term outcomes. Four patients (7%) had small coronary aneurysms at presentation, all of which resolved. Only 1 of 9 patients had residual edema but no fibrosis by cardiac magnetic resonance imaging. Conclusions Our short-term study suggests that functional recovery and coronary outcomes are good in multisystem inflammatory syndrome in children. Use of sensitive deformation parameters provides further reassurance that there is no persistent subclinical dysfunction after 3 months.

Skewed Cytokine Responses Rather Than the Magnitude of the Cytokine Storm May Drive Cardiac Dysfunction in Multisystem Inflammatory Syndrome in Children.

Background Cardiac dysfunction is a prominent feature of multisystem inflammatory syndrome in children (MIS-C), yet the etiology is poorly understood. We determined whether dysfunction is global or regional, and whether it is associated with the cytokine milieu, microangiopathy, or severity of shock. Methods and Results We analyzed echocardiographic parameters of myocardial deformation and compared global and segmental left ventricular strain between 43 cases with MIS-C ≤18 years old and 40 controls. Primary outcomes included left ventricular global longitudinal strain, right ventricular free wall strain), and left atrial strain. We evaluated relationships between strain and profiles of 10 proinflammatory cytokines, microangiopathic features (soluble C5b9), and vasoactive-inotropic requirements. Compared with controls, cases with MIS-C had significant impairments in all parameters of systolic and diastolic function. 65% of cases with MIS-C had abnormal left ventricular function (|global longitudinal strain|<17%), although elevations of cytokines were modest. All left ventricular segments were involved, without apical or basal dominance to suggest acute stress cardiomyopathy. Worse global longitudinal strain correlated with higher ratios of interleukin-6 (ρ -0.43) and interleukin-8 (ρ -0.43) to total hypercytokinemia, but not absolute levels of interleukin-6 or interleukin-8, or total hypercytokinemia. Similarly, worse right ventricular free wall strain correlated with higher relative interleukin-8 expression (ρ -0.59). There were no significant associations between function and microangiopathy or vasoactive-inotropic requirements. Conclusions Myocardial function is globally decreased in MIS-C and not explained by acute stress cardiomyopathy. Cardiac dysfunction may be driven by the relative skew of the immune response toward interleukin-6 and interleukin-8 pathways, more so than degree of hyperinflammation, refining the current paradigm of myocardial involvement in MIS-C.

Multisystem Inflammatory Syndrome in Children During the Coronavirus 2019 Pandemic: A Case Series.

We present a series of 6 critically ill children with multisystem inflammatory syndrome in children. Key findings of this syndrome include fever, diarrhea, shock, and variable presence of rash, conjunctivitis, extremity edema, and mucous membrane changes.