Impact of intravenous immunoglobulin infusion on longitudinal left ventricular performance in patients with acute Kawasaki disease of usual course

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

BACKGROUND

N-terminal of pro-brain natriuretic peptide (NT-proBNP) and C-reactive protein (CRP) levels are often elevated in Multisystem Inflammatory Syndrome in Children (MIS-C) secondary to inflammation, myocardial dysfunction, or increased wall tension. Intravenous Immunoglobulin (IVIG), accepted treatment for MIS-C, may transiently increase myocardial tension and contribute to an increase in NT-proBNP.

OBJECTIVE

We sought to study the association between pre- and post-IVIG levels of NT-proBNP and CRP and their clinical significance.

METHODS

This single center retrospective cohort study included consecutive children, ages ≤ 21 years, with diagnosis of MIS-C who received IVIG from April 2020 through October 2021. Data collection included clinical characteristics, laboratory tests, management, and outcomes. Study cohort consisted of patients who received IVIG and had NT-proBNP levels available pre- and post-IVIG.

RESULTS

Among 35 patients with MIS-C, 30 met inclusion criteria. Twenty-four, 80%, showed elevation in NT-proBNP post-IVIG. The median NT-proBNP level pre-IVIG was 1,921 pg/mL (IQR 548, 3,956), significantly lower than the post-IVIG median of 3,756 pg/mL (IQR 1,342, 7,634)) (p=0.0010). The median pre-IVIG CRP level was significantly higher than the post-IVIG level (12 mg/dL vs 8 mg/dL, p= 0.0006). All but one recovered prior to discharge, and none had signs of worsening cardiac function post-IVIG. In those who recovered, NT-proBNP had normalized by discharge or 1-week follow-up.

CONCLUSIONS

Our study shows that NT-proBNP levels often transiently increase immediately after IVIG therapy without signs of worsening myocardial function. These values should be interpreted in the context of CRP levels and clinical recovery.

Z-score of Mitral Annular Plane Systolic Excursion is a Useful Indicator of Evaluation of Left Ventricular Function in Patients with Acute-Phase Kawasaki Disease

We previously reported the clinical usefulness of the mitral annular plane systolic excursion (MAPSE) to evaluate the left ventricular (LV) function in patients with Kawasaki disease (KD) in the acute-phase. However, the feasibility of the MAPSE z-score has not been evaluated in patients with acute KD. We prospectively studied 60 KD patients without coronary aneurysms. The MAPSE z-scores were calculated using our standard MAPSE data. Brain natriuretic peptide (BNP) was measured as a parameter of LV function. In total, 281 healthy age- and body size-matched subjects were chosen as the control group. The MAPSE z-score decreased in the acute-phase (median value, -1.4) and increased in the convalescent phase (median value, 0.18; P < 0.0001). However, there was no significant difference in the MAPSE z-score between patients in the convalescent phase and the control patients (0.18 vs. 0.02, P = 0.199). Multivariate regression analysis revealed that BNP was an independent predictor of the MAPSE z-score (β = 0.40, P < 0.005). According to the receiver operating characteristic (ROC) analysis, the optimal cutoff value for the MAPSE z-score to judge LV dysfunction was -0.9. The MAPSE z-score is a useful index to evaluate LV function, and the cutoff value of -0.9 can be an indicator to judge LV dysfunction in the patients with acute-phase KD.

Tissue Doppler Imaging as a Predictor of Immunoglobulin Resistance in Kawasaki Disease

Kawasaki disease (KD) is characterized by myocarditis and left ventricular dysfunction during the acute phase of the illness. Despite treatment with intravenous immunoglobulin (IVIG), a significant number of patients are IVIG resistant. We evaluated KD patients in the acute phase of illness using tissue Doppler imaging (TDI) to assess whether myocardial dysfunction may predict IVIG resistance. All patients with acute KD presenting to Children's Hospital Colorado from February 2007 through March 2014 were included in this study and underwent echocardiograms with TDI evaluation at diagnosis. Patients were divided into two groups: IVIG resistant and IVIG responder. Group differences were assessed using Wilcoxon-Mann-Whitney and Chi-square testing. Receiver operating characteristic (ROC) curve analysis was utilized to determine threshold values of TDI measurements associated with IVIG resistance. Fifty-one age-matched IVIG resistant patients were compared to 51 IVIG responder patients [median age, IQR 44.57 (20.13-77.07) vs. 33.49 (17.30-62.89) months, p < 0.44]. There were significant differences in the septal and mitral early diastolic velocities (E') (p < 0.001 and p < 0.01), respectively. ROC analysis demonstrated that tricuspid E' <0.15 cm/s, septal E' <0.12 cm/s, and mitral E' <0.16 cm/s were good predictors of IVIG unresponsiveness (AUC = 0.66, 0.66, and 0.70, respectively). There were no differences between the systolic velocities and late diastolic velocities (A'). IVIG resistant KD patients present with significantly greater diastolic dysfunction compared to responders in patients with KD. TDI may be a useful tool to differentiate KD patients at higher risk of IVIG resistance.

Impairment of Left Ventricular Longitudinal Contraction is Associated with Serum Brain Natriuretic Peptide Concentration in Patients with Acute-Phase Kawasaki Disease

It is well known that brain natriuretic peptide (BNP) is elevated in the acute phase of Kawasaki disease (KD). We hypothesized that mitral annular plane systolic excursion (MAPSE) could identify LV dysfunction in the acute phase of KD. Fifty patients with KD were enrolled in this study. BNP sampling and an echocardiographic study were performed just before and after intravenous immunoglobulin administration. MAPSE was measured in M-mode in the apical four-chamber view. The %MAPSE was calculated as the MAPSE measured in the acute phase divided by that measured in the convalescent phase. We compared the acute and the convalescent phases of KD. The values of the MAPSE were significantly reduced (45 out of 50 patients) during the acute phase and immediately recovered in the convalescent phase (10.0 ± 1.9 vs. 12.7 ± 1.9 mm, P < 0.0001). Of the parameters tested, %MAPSE was the only echocardiographic parameter that was associated with Log-BNP. Additionally, %MAPSE had a significant negative correlation with Log-BNP (r = -0.45, P < 0.0039). Longitudinal LV contraction is impaired in the acute phase of KD, but it immediately recovers in the convalescent phase. Measuring the longitudinal LV contractility should be essential for evaluating LV function in the acute phase of KD, and MAPSE is useful for this evaluation.