NT-proBNP Levels Following IVIG Treatment for Multisystem Inflammatory Syndrome in Children

Clinical Significance of B-Type Natriuretic Peptide and N-Terminal Pro-B-Type Natriuretic Peptide in Pediatric Patients: Insights into Their Utility in the Presence or Absence of Pre-Existing Heart Conditions

The clinical significance of B-type natriuretic peptide (BNP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in pediatric patients remains an area of evolving understanding, particularly regarding their utility in the presence or absence of pre-existing heart conditions. While clear cutoff values and established roles in heart failure are understood in adult patients, pediatric norms vary with age, complicating interpretation. Notably, the emergence of multi-system inflammatory syndrome in children (MIS-C) has highlighted the importance of these markers not only in the detection of acute heart failure but also as a marker of disease severity and even as a differential diagnosis tool. This review summarizes current knowledge on the utility of BNP and NT-proBNP in pediatric patients. Their unique physiology, including circulation and compensation mechanisms, likely influence BNP and NT-proBNP release, potentially even in non-heart failure states. Factors such as dynamic volemic changes accompanying inflammatory diseases in children may contribute. Thus, understanding the nuanced roles of BNP and NT-proBNP in pediatric populations is crucial for the accurate diagnosis, management, and differentiation of cardiac and non-cardiac conditions.

NT-proBNP course during MIS-C post-COVID-19: an observational study

Multisystem inflammatory syndrome in children (MIS-C or PIMS-TS) is a severe disease. N-terminal pro-B-type natriuretic peptide (NT-proBNP) is used for positive and differential diagnosis, diagnosis of complications and severity, and cardiogenic shock prediction. However, contrasting cut-offs have been suggested. The aims of the present study were to compare NT-proBNP values depending on the time of measurement and to describe the NT-proBNP course during the MIS-C episode. The data from a single-centre cohort observational study on the impact of time to diagnosis, defined as the time from first symptom to diagnosis of MIS-C, were used for the purpose of this study, with an extended period of inclusion from May 2020 to April 2023. The timing and level of all NT-proBNP samples available for each patient were retrospectively collected. Thirty-seven children (18 (49%) females, median age 8.8 years, 14 (38%) with shock) were included. Until diagnosis, NT-proBNP increased with time and was significantly higher at 6 days from first symptoms than at 3 days (median (interquartile range) 32,933 (7773-61,592) versus 1994 (1291-4190) pg/mL, respectively, p = 0.031). From diagnosis, NT-proBNP decreased by at least 50% after 3.0 (2.1-5.3) days (n = 12) when NT-proBNP at diagnosis was low ≤ 11,000 pg/mL versus 1.8 (0.7-3.4) days (n = 16) when NT-proBNP at diagnosis was high (p = 0.040), and after 3.6 (2.4-5.9) days (n = 7) when fever persisted after 48 h versus 1.8 (0.8-3.0) days (n = 21) when fever resolved before 48 h (p = 0.004).  Conclusions: During the MIS-C episode, NT-proBNP increased over time until diagnosis and treatment. It dropped faster thereafter in children with high NT-proBNP at diagnosis > 11,000 pg/mL and slower in case of persistent fever. What is Known: • NT-proBNP is useful in MIS-C for positive and differential diagnosis, diagnosis of complications and severity, and cardiogenic shock prediction. • Contrasting cut-offs for differential diagnosis and severity assessment have been suggested. What is New: • Before diagnosis, NT-proBNP increases with time and is significantly higher at 6 days from first symptoms than at 3 days suggesting different cut-offs depending on the timing of measurement. • From diagnosis and treatment initiation, the 50% NT-proBNP drop occurs earlier in children with high NT-proBNP at diagnosis > 11,000 pg/mL and later in children with persistent fever.

Clinical Predictors of Subacute Myocardial Dysfunction in Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with COVID-19

Multisystem Inflammatory Syndrome in Children (MIS-C) often involves a post-viral myocarditis and associated left ventricular dysfunction. We aimed to assess myocardial function by strain echocardiography after hospital discharge and to identify risk factors for subacute myocardial dysfunction. We conducted a retrospective single-center study of MIS-C patients admitted between 03/2020 and 03/2021. Global longitudinal strain (GLS), 4-chamber longitudinal strain (4C-LS), mid-ventricular circumferential strain (CS), and left atrial strain (LAS) were measured on echocardiograms performed 3-10 weeks after discharge and compared with controls. Among 60 MIS-C patients, hypotension (65%), ICU admission (57%), and vasopressor support (45%) were common, with no mortality. LVEF was abnormal (< 55%) in 29% during hospitalization but only 4% at follow-up. Follow-up strain abnormalities were prevalent (GLS abnormal in 13%, 4C-LS in 18%, CS in 16%, LAS in 5%). Hypotension, ICU admission, ICU and hospital length of stay, and any LVEF < 55% during hospitalization were factors associated with lower strain at follow-up. Higher peak C-reactive protein (CRP) was associated with hypotension, ICU admission, total ICU days, and with lower follow-up GLS (r = - 0.55; p = 0.01) and CS (r = 0.41; p = 0.02). Peak CRP < 18 mg/dL had negative predictive values of 100% and 88% for normal follow-up GLS and CS, respectively. A subset of MIS-C patients demonstrate subclinical systolic and diastolic function abnormalities at subacute follow-up. Peak CRP during hospitalization may be a useful marker for outpatient cardiac risk stratification. MIS-C patients with hypotension, ICU admission, any LVEF < 55% during hospitalization, or a peak CRP > 18 mg/dL may warrant closer monitoring than those without these risk factors.

Nutraceuticals for Complementary Treatment of Multisystem Inflammatory Syndrome in Children: A Perspective from Their Use in COVID-19

Multisystem inflammatory syndrome in children (MIS-C) has been widely reported in some children diagnosed with SARS-CoV-2. Clinical signs of MIS-C are manifested at 2 to 4 weeks after SARS-CoV-2 infection, where elevated biomarkers of inflammation and cardiac dysfunction are the hallmark of this syndrome when infection or exposure to SARS-CoV-2 has been confirmed. However, after two years of acknowledgment, MIS-C treatment is still under research to reach safety and effectiveness in the acute phase in children. Therefore, in this review, we discuss the potential use of natural compounds with antioxidant and anti-inflammatory effects to reduce collateral damage caused by hyperinflammation in MIS-C pathology for new research in treatment and interventions.