Noncoronary cardiac abnormalities are associated with coronary artery dilation and with laboratory inflammatory markers in acute Kawasaki disease

New Insights into the Pathophysiology of Coronary Artery Aneurysms

Coronary aneurysms are typically defined as sections of a coronary artery where the diameter is more than 1.5 times that of an adjacent normal segment. In rare circumstances, these aneurysms can become exceedingly large, leading to the classification of giant coronary artery aneurysms. Despite their occurrence, there is no clear consensus on the precise definition of giant coronary artery aneurysms, and their etiology remains somewhat ambiguous. Numerous potential causes have been suggested, with atherosclerosis being the most prevalent in adults, accounting for up to 50% of cases. In pediatric populations, Kawasaki disease and Takayasu arteritis are the primary causes. Although often discovered incidentally, coronary artery aneurysms can lead to severe complications. These complications include local thrombosis, distal embolization, rupture, and vasospasm, which can result in ischemia, heart failure, and arrhythmias. The optimal approach to medical, interventional, or surgical management of these aneurysms is still under debate and requires further clarification. This literature review aims to consolidate current knowledge regarding coronary artery aneurysms' pathophysiology, emphasizing their definition, causes, complications, and treatment strategies. Recent research has begun to explore the molecular mechanisms involved in the formation and progression of coronary artery aneurysms. Various molecules, such as matrix metalloproteinases (MMPs), inflammatory cytokines, and growth factors, play crucial roles in the degradation of the extracellular matrix and the remodeling of vascular walls. Elevated levels of MMPs, particularly MMP-9, have been associated with the weakening of the arterial wall, contributing to aneurysm development. Inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukins (IL-1β and IL-6) have been implicated in promoting inflammatory responses that further degrade vascular integrity. Additionally, growth factors such as vascular endothelial growth factor (VEGF) may influence angiogenesis and vascular remodeling processes. Understanding these molecular pathways is essential for developing targeted therapies aimed at preventing the progression of coronary artery aneurysms and improving patient outcomes.

Coronary Artery Aneurysms: A Clinical Case Report and Literature Review Supporting Therapeutic Choices

Coronary artery aneurysms (CAAs) are uncommon but significant cardiovascular abnormalities characterized by an abnormal increase in vascular diameter. CAAs are classified based on their shape as either saccular or fusiform, and their causes can range from atherosclerosis, Kawasaki disease, to congenital and iatrogenic factors. CAAs often present asymptomatically, but when symptoms occur, they can include angina, myocardial infarction, or even sudden cardiac death due to intravascular thrombosis involving the CAA. Diagnosis is typically confirmed through coronary angiography, though CT and other imaging techniques can provide additional details. The management of CAAs is variable depending on their size, location, and the presence of symptoms or complications. Treatment options include medical therapy, percutaneous coronary intervention (PCI), or surgical approaches. In this paper, we describe the case report of a 79-year-old male who presented with palpitations and was diagnosed with a right coronary artery aneurysm, and a review of the literature is delineated, underscoring the importance of individualized treatment strategies for CAAs.

Coronary Arteries Lesions in Kawasaki Disease: Risk Factors in an Italian Cohort

Background: Kawasaki disease (KD) is a systemic vasculitis of medium arteries, particularly involving coronary arteries. Coronary artery lesions (CALs) is the most serious complication in the acute stage, potentially leading to ischemic cardiomyopathy, myocardial infarction and sudden death. Environmental factors and genetic background contribute to individual susceptibility to develop CALs. The aim of this study was to define the risk factors for CALs in an Italian cohort. Methods: Data of KD patients from 10 Italian sites were registered into a REDCap database where demographic and clinical data, laboratory findings and coronary status were recorded. KD was diagnosed according to AHA definition. We used multiple logistic regression analysis to identify independent risk factors for CALs. Results: A total of 517 patients were enrolled, mainly Caucasians (83.6%). Presentation was complete in 321 patients (62.8%) and IVIG responsiveness in 360 (70%). CALs developed in 136/517 (26.31%). Gender, age, ethnicity, clinical presentation, fever duration, non-coronary cardiac events, Hb, albumin and CRP were significantly different between patients with and without CALs, while seasonality was not. Male gender, age < 18 months, Asian ethnicity, incomplete presentation and fever > 10 days were independent risk factors for CALs. Conclusions: Age younger than 18 months, incomplete KD and longer fever duration are risk factors for CALs. Asian ethnicity also represents a risk factor in our Italian Cohort.

The Central Role of Interleukin-1 Signalling in the Pathogenesis of Kawasaki Disease Vasculitis: Path to Translation

Kawasaki disease (KD) manifests as an acute febrile condition and systemic vasculitis, the etiology of which remains elusive. Primarily affecting children under 5 years of age, if untreated KD can lead to a significant risk of coronary artery aneurysms and subsequent long-term cardiovascular sequelae, including myocardial ischemia and myocardial infarction. Intravenous immunoglobulin therapy mitigates the risk of aneurysm formation, but a subset of patients exhibit resistance to this treatment, increasing the susceptibility of coronary artery lesions. Furthermore, the absence of a KD-specific diagnostic test or biomarkers complicates early detection and appropriate treatment. Experimental murine models of KD vasculitis have substantially improved our understanding of the disease pathophysiology, revealing the key roles of the NLRP3 inflammasome and interleukin-1 (IL-1) signalling pathway. This review aims to delineate the pathophysiologic findings of KD while summarising the findings for the emerging key role of IL-1β in its pathogenesis, derived from both human data and experimental murine models, and the translational potential of these findings for anti-IL-1 therapies for children with KD.

Pan-valvulitis in Children With Kawasaki Disease: A Case Report and Review of the Literature

We present a rare case of pan-valvular involvement in a 5-month-old female with Kawasaki disease shock syndrome despite early treatment with intravenous immunoglobulin and corticosteroids. She experienced a favorable outcome after the addition of infliximab, which was guided based on clinical, laboratory and echocardiogram findings, rather than recrudescence of fever, the most common indicator of intravenous immunoglobulin resistance.

Retrospective evaluation of 130 cases with kawasaki disease follow-up in a tertiary care center in Turkey between 1999 and 2019: a 20-year experience

OBJECTIVES

Kawasaki disease (KD), which is a medium vessel vasculitis, is common in Asian countries and is the most common cause of childhood-acquired heart diseases in developed countries. However, disease course and epidemiological data are limited in non-Asian developing countries like ours. We aimed to evaluate the clinical features and prognosis of patients with KD in our country and ethnicity, one of the referee centers of our country.

METHODS

Patients with KD in our center for the last 20 years in the pre-COVID-19 pandemic era were included in the study. The clinical and laboratory findings, treatments, and follow-up findings were reviewed retrospectively in different age groups.

RESULTS

Of the 130 patients, 82 (63%) were male. The median age at diagnosis was 2.97 years (2 months-11.5 years). Thirty-six (27.7%) patients were diagnosed with incomplete KD, and there was no significant laboratory difference between incomplete KD and complete KD patients. Thirty-three (25.3%) patients had coronary artery lesions (CAL), and it persisted in only 3 of 33 patients. One of 15 patients with IVIG resistance had CAL. The independent risk factors were days of illness at initial IVIG administration for CAL (p = 0.013, OR [95%CI] = 1.20 [1.04-1.38]) and low hemoglobin (p = 0.003, OR [95%CI] = 0.51 [0.33-0.79]) and low sodium for IVIG resistance (p = 0.012, OR [95%CI] = 0.81[0.69-0.95]).

CONCLUSIONS

The rate of CAL is approximately three times higher in our results than in the Japanese data in recent years. We showed that the time of IVIG administration is the most critical factor for preventing CAL. Wide-ranging studies are needed to decently predict the disease process according to the age and region of patients.

A rare case of coronary artery complication in a child with systemic juvenile idiopathic arthritis and macrophage activation syndrome: case report and literature review

A rare case of coronary artery involvement in a child with Systemic Juvenile Idiopathic Arthritis (sJIA) complicated by Macrophage Activation Syndrome (MAS) is reported. The patient initially received an inaccurate diagnosis of Kawasaki Disease, sepsis, and mycoplasma infection and showed no improvement after Intravenous Immune Globulin (IVIG) treatment. Upon admission, symptoms included diffuse red rash, swelling of the limbs, lymph node enlargement, and hepatosplenomegaly. Post investigations, a diagnosis of sJIA and MAS was confirmed, and treatment involved a combination of hormones (methylprednisolone) and immunosuppressive drugs (methotrexate). The revealed widened coronary artery diameter was managed with a disease-specific treatment plan and prophylactic plus low-dose aspirin anti-coagulation therapy. Under this management, MAS was well controlled, and follow-ups showed normalization of the child's coronary artery structure and function. This case and the associated literature review underscore the importance of early recognition, diagnosis, treatment, and long-term monitoring for children presenting with sJIA and MAS complicated by coronary artery involvement.

Childhood rheumatic diseases: bites not only the joint, but also the heart

Cardiovascular involvement in juvenile rheumatic diseases is the primary manifestation in paediatric vasculitis and a major organ manifestation in paediatric connective tissue diseases. Though coronary vasculitis is the prototypical manifestation of Kawasaki disease, it can also be seen in patients with polyarteritis nodosa. Pericarditis is the most common manifestation seen in juvenile rheumatic diseases like systemic onset JIA, and lupus. Cardiac tamponade, valvular insufficiency, aortic root dilatation and arrhythmias are seen rarely. Cardiac involvement is often recognized late in children. The development of cardiac disease in juvenile systemic sclerosis is associated with a poor outcome. In long term, childhood onset of rheumatic diseases predisposes to diastolic dysfunction and premature atherosclerosis during adulthood. Key Points • Pericarditis is the most common cardiac manifestation in SLE and can lead to tamponade. • Conduction defects are common in juvenile mixed connective tissue disease and systemic sclerosis. • Pulmonary hypertension is a significant contributor to mortality in juvenile systemic sclerosis. • In Kawasaki disease, early treatment can reduce risk of coronary artery aneurysms.

Multisystem Inflammatory Syndrome in Children and Kawasaki Disease: A Spectrum of Postinfectious Hyperinflammatory Disease

Kawasaki disease and multisystem inflammatory syndrome in children are hyperinflammatory conditions that share similar emerging pathophysiology hypotheses, clinical features, treatment strategies, and outcomes. Although both conditions have key differences, growing evidence suggests that both conditions might be closely related on a larger spectrum of postinfectious autoimmune responses.

French national diagnostic and care protocol for Kawasaki disease

Kawasaki disease (KD) is an acute vasculitis with a particular tropism for the coronary arteries. KD mainly affects male children between 6 months and 5 years of age. The diagnosis is clinical, based on the international American Heart Association criteria. It should be systematically considered in children with a fever, either of 5 days or more, or of 3 days if all other criteria are present. It is important to note that most children present with marked irritability and may have digestive signs. Although the biological inflammatory response is not specific, it is of great value for the diagnosis. Because of the difficulty of recognising incomplete or atypical forms of KD, and the need for urgent treatment, the child should be referred to a paediatric hospital as soon as the diagnosis is suspected. In the event of signs of heart failure (pallor, tachycardia, polypnea, sweating, hepatomegaly, unstable blood pressure), medical transfer to an intensive care unit (ICU) is essential. The standard treatment is an infusion of IVIG combined with aspirin (before 10 days of fever, and for a minimum of 6 weeks), which reduces the risk of coronary aneurysms. In case of coronary involvement, antiplatelet therapy can be maintained for life. In case of a giant aneurysm, anticoagulant treatment is added to the antiplatelet agent. The prognosis of KD is generally good and most children recover without sequelae. The prognosis in children with initial coronary involvement depends on the progression of the cardiac anomalies, which are monitored during careful specialised cardiological follow-up.

Cardiovascular outcomes in children with Kawasaki disease: a population-based cohort study

BACKGROUND

The risk of cardiovascular events after Kawasaki disease (KD) remains uncertain. Our objective was to determine the risk of cardiovascular events and mortality after KD.

METHODS

Population-based retrospective cohort study using Ontario health administrative databases (0-18 years; 1995-2018).

EXPOSURE

pediatric KD hospitalizations. Each case was matched to 100 non-exposed controls.

PRIMARY OUTCOME

major adverse cardiac events (MACE; cardiovascular death, myocardial infarction, or stroke composite).

SECONDARY OUTCOMES

composite cardiovascular events and mortality. We determined incidence rates and adjusted hazard ratios (aHR) using multivariable Cox models.

RESULTS

Among 4597 KD survivors, 79 (1.7%) experienced MACE, 632 (13.8%) composite cardiovascular events, and 9 (0.2%) died during 11-year median follow-up. The most frequent cardiovascular events among KD survivors were ischemic heart disease (4.6 events/1000 person-years) and arrhythmias (4.5/1000 person-years). KD survivors were at increased risk of MACE between 0-1 and 5-10 years, and composite cardiovascular events at all time periods post-discharge. KD survivors had a lower mortality risk throughout follow-up (aHR 0.36, 95% CI 0.19-0.70).

CONCLUSION

KD survivors are at increased risk of post-discharge cardiovascular events but have a lower risk of death, which justifies enhanced cardiovascular disease surveillance in these patients.

IMPACT

Among 4597 Kawasaki disease (KD) survivors, 79 (1.7%) experienced major adverse cardiac events (MACE) and 632 (13.8%) had composite cardiovascular events during 11-year median follow-up. KD survivors had significantly higher risks of post-discharge MACE and cardiovascular events versus non-exposed children. Only nine KD survivors (0.2%) died during follow-up, and the risk of mortality was significantly lower among KD survivors versus non-exposed children. Childhood KD survivors should receive preventative counseling and cardiovascular surveillance, aiming to mitigate adult cardiovascular disease.

Cardiovascular Outcomes During Index Hospitalization in Children with Kawasaki Disease in Ontario, Canada

Kawasaki disease (KD) is a common childhood vasculitis associated with coronary artery aneurysms (CAA). However, there is limited published data on other cardiovascular events diagnosed during acute KD hospitalizations. Our objectives were to determine the incidence of cardiovascular events during acute KD hospitalizations, stratified by age at admission, CAA status, and pediatric intensive care unit (PICU) admission status. We identified all children (0-18 year) hospitalized with a new KD diagnosis in Ontario, between 1995 and 2018, through validated algorithms using population health administrative databases. We excluded children previously diagnosed with KD and non-Ontario residents. We evaluated for cardiovascular events that occurred during the acute KD hospitalizations, defined by administrative coding. Among 4597 children hospitalized with KD, 3307 (71.9%) were aged 0-4 years, median length of stay was 3 days (IQR 2-4), 113 children (2.5%) had PICU admissions, and 119 (2.6%) were diagnosed with CAA. During acute hospitalization, 75 children were diagnosed with myocarditis or pericarditis (1.6%), 47 with arrhythmias (1.0%), 25 with heart failure (0.5%), and ≤ 5 with acute MI (≤ 0.1%). Seven children underwent cardiovascular procedures (0.2%). Older children (10-18 years), children with CAA, and children admitted to the PICU were more likely to experience cardiovascular events, compared with children aged 0-4 years, without CAA or non-PICU admissions, respectively. The frequency of non-CAA cardiovascular events during acute KD hospitalizations did not change significantly between 1995 and 2018. During acute KD hospitalizations, older children, children with CAA, and PICU admissions are at higher risk of cardiovascular complications, justifying closer monitoring of these high-risk individuals.

Immune and non-immune mechanisms that determine vasculitis and coronary artery aneurysm topography in Kawasaki disease and MIS-C

The overlap between multisystem inflammatory syndrome in children (MIS-C) and Kawasaki disease (KD) including coronary artery aneurysms (CAA) and broadly shared gastrointestinal and mucocutaneous disease is poorly defined. In this perspective, we highlight common age-related extravascular epicardial microanatomical and immunological factors that might culminate in CAA expression in both MIS-C and KD. Specifically, the coronary vasa vasorum originates outside the major coronary arteries. Widespread inflammation in the epicardial interstitial compartment in shared between KD and MIS-C. Age-related changes in the neonatal and immature coronary vasculature including the impact of coronary artery biomechanical factors including coronary vessel calibre, age-related vessel distensibility, flow, and vessel neurovascular innervation may explain the decreasing CAA frequency from neonates to older children and the virtual absence of CAA in young adults with the MIS-C phenotype. Other KD and MIS-C features including mucocutaneous disease with keratinocyte-related immunopathology corroborate that disease phenotypes are centrally influenced by inflammation originating outside vessel walls but a potential role for primary coronary artery vascular wall inflammation cannot be excluded. Hence, common extravascular originating tissue-specific responses to aetiologically diverse triggers including superantigens may lead to widespread interstitial tissue inflammation characteristically manifesting as CAA development, especially in younger subjects. Given that CAA is virtually absent in adults, further studies are needed to ascertain whether epicardial interstitial inflammation may impact on both coronary artery physiology and cardiac conduction tissue and contribute to cardiovascular disease- a hitherto unappreciated consideration.

Predictive role of sampling-time specific prognostic nutritional index cut-off values for intravenous immunoglobulin resistance and cardiovascular complications in Kawasaki disease

BACKGROUND

Intravenous immunoglobulin (IVIG) resistance and cardiovascular complications prediction are pivotal topic of interests in Kawasaki disease (KD). The prognostic nutritional index (PNI) has been proposed to be valuable in predicting the severity of inflammatory status and prognosis in clinical circumstances, with limited data in KD. Therefore, we prospectively investigated the role of sampling-time specific PNI cut-off values in predicting initial IVIG resistance as well as cardiovascular complications in patients with KD for the first time.

METHODS

A total of 755 patients with KD were prospectively recruited between January 2015 and December 2019. Patients with KD were subgrouped based on the presence of IVIG resistance or cardiovascular complications. The clinical and laboratory parameters were compared. Multivariate logistic regression analysis was performed to identify the independent risk factors for IVIG resistance and cardiovascular complications. The receiver operating characteristic (ROC) curve was further applied to assess the predictive values of PNI in IVIG resistance and cardiovascular complications.

RESULTS

The lower level of PNI was identified as independent risk factors for initial IVIG resistance and cardiovascular complications. The discriminating cut-off values of the PNI for IVIG resistance, all cardiovascular complications, CALs, KDSS and myocarditis were 47.8, 52.2, 38.6, 48.2 and 52.0, with the corresponding sensitivities of 0.573, 0.679, 0.174, 0.750, 0.851, and specificities of 0.753, 0.549, 0.957, 0.679 and 0.576, respectively. After sampling time stratification, the sensitivities and specificities of the PNI obtained at the sixth day from fever onset for prediction of both IVIG resistance (0.778, 0.787) and all cardiovascular complications (0.667, 0.753) remarkably improved.

CONCLUSION

PNI may serve as a promising predictor for KDSS in patients with KD. PNI obtained at sixth day from fever onset possess good predictive power for both IVIG resistance and all cardiovascular complications in KD.

Clinical Manifestations and Laboratory Findings of Kawasaki Disease: Beyond the Classic Diagnostic Features

Kawasaki disease (KD) has shown a marked increase in trend over the globe, especially within the last two decades. Kawasaki disease is often seen in the paediatric population below five years old, while it is rare for those who are beyond that age. Up to this date, no exact causes has been identified although KD was found more than half a century ago. The underlying pathogenesis of the disease is still unelucidated, and researchers are trying to unlock the mystery of KD. To further complicate the diagnosis and the prompt management, a specific biomarker for the diagnosis of KD is yet to be discovered, making it hard to differentiate between KD and other diseases with a similar presentation. Nonetheless, since its discovery, clinicians and scientists alike had known more about the different clinical aspects of typical KD. Thus, this article intends to revisit and review the various clinical manifestations and laboratory characteristics of KD in order to guide the diagnosis of KD.

Practical Workflow for Cardiovascular Assessment and Follow-Up in Kawasaki Disease Based on Expert Opinion

BACKGROUND

Approximately 25% of the patients with a history of Kawasaki disease (KD) develop coronary artery pathology if left untreated, with coronary artery aneurysms (CAA) as an early hallmark. Depending on the severity of CAAs, these patients are at risk of myocardial ischemia, infarction and sudden death. In order to reduce cardiac complications it is crucial to accurately identify patients with coronary artery pathology by an integrated cardiovascular program, tailored to the severity of the existing coronary artery pathology.

METHODS

The development of this practical workflow for the cardiovascular assessment of KD patients involve expert opinions of pediatric cardiologists, infectious disease specialists and radiology experts with clinical experience in a tertiary KD reference center of more than 1000 KD patients. Literature was analyzed and an overview of the currently most used guidelines is given.

CONCLUSIONS

We present a patient-specific step-by-step, integrated cardiovascular follow-up approach based on expert opinion of a multidisciplinary panel with expertise in KD.

Evaluation of comprehensive myocardial contractility in children with Kawasaki disease by cardiac magnetic resonance in a large single center

BACKGROUND

Children with Kawasaki disease (KD) and coronary artery lesions (CALs) can develop myocardial ischemia, fibrosis, and abnormal contractility. We aimed to assess the association between myocardial mechanical deformation with myocardial fibrosis, ischemia, and CALs.

METHODS

In total, 76 KD and 20 healthy volunteers received cardiac magnetic resonance (CMR). Peak systolic left ventricular (LV) longitudinal, radial, and circumferential strain and strain rate [LV strain longitudinal (LVSL), LV strain radial (LVSR), LV strain circumferential (LVSC), LV strain rate longitudinal (LVSRL), LV strain rate radial (LVSRR), and LV strain rate circumferential (LVSRC)], along with late gadolinium enhancement (LGE), perfusion deficit, and CALs in related segments were analyzed. The KD group was subdivided by CALs, perfusion, and LGE results, and strain results were compared with controls and in subgroups.

RESULTS

Cardiac fibrosis and ischemia were not confined to the territory of CALs. In a global analysis, strain and strain rates were lower in the KD group, especially in the subgroup with LGE and perfusion deficit. In segmental analysis, LVSR, LVSC, LVSL, and LVSRR decreased in the giant aneurysm group, and a lower LVSR (20.369%±10.603% vs. 26.071%±12.349%) and LVSC (-13.37%±5.365% vs. -15.847%±5.778%) were observed in thrombosed segments. The strain and strain rate were all lower in segments with LGE and perfusion deficit, and no obvious difference was found between groups with and without stenosis. LVSR had a better ability to identify giant aneurysm, thrombosis, stenosis, perfusion deficit, and LGE.

CONCLUSIONS

We detected lower strain values in KD patients, which was more pronounced in segments with aneurysm, thrombi, LGE, and perfusion deficit. LVSR is useful to discern patients with higher risk.

A new scoring system for coronary artery abnormalities in Kawasaki disease

BACKGROUND

In China, coronary artery abnormalities (CAAs) secondary to Kawasaki disease (KD) tend to have an increased occurrence. We hypothesize that Chinese children with KD may possess several unique CAA risks, and the predictive efficacy of multiple scoring systems in Chinese patients are still to be further studied.

METHODS

Two hundred and three KD patients were recruited. Using multivariable analysis, independent predictors of CAAs were combined into a scoring system. Subsequently, CAA risks of our patients were evaluated by the newly established scoring system and eight other published scoring systems.

RESULTS

Seventeen (8.37%) KD patients were identified as CAAs. The newly established scoring system contained the following 5 independent predictors: days of illness at initial treatment ≥7, redness and swelling of extremities, hematocrit ≤33%, percentage of monocytes ≥8.89%, and procalcitonin ≥0.5 ng/mL. The AUC value of newly established scoring system was 0.685 with a sensitivity of 41.18% and a specificity of 84.41%, higher than Harada score, Egami score, Kobayashi score, Sato score, San Diego score, Formosa score, and Tang score, whereas lower than Hua score.

CONCLUSIONS

Days of illness at initial treatment ≥7 and procalcitonin are unique predictors of CAAs in newly established scoring system. Taking into account different identification criteria and analytical methodologies, there is still some heterogeneity among different scoring systems.

IMPACT

The newly established scoring system contains the five independent predictors. Days of illness at initial treatment ≥7 and PCT are unique predictors of CAAs in our study, compared with 8 other systems. The AUC value of newly established scoring system is 0.685, similar to Hua score. There is some heterogeneity among different scoring systems.

Multisystem Imaging Manifestations of Kawasaki Disease

Kawasaki disease (KD) is a common pediatric vasculitis syndrome involving medium- and small-sized arteries that is especially prevalent in early childhood (ie, age 6 months to 5 years). The diagnosis of KD is made on the basis of clinical features, such as fever, characteristic mucocutaneous changes, and nonsuppurative cervical lymphadenopathy. However, early diagnosis is often challenging because many children with KD present with atypical symptoms. The most serious complication of KD is coronary artery aneurysm caused by coronary arteritis. Prompt intravenous immunoglobulin therapy reduces the risk of cardiac morbidity. In addition, the systemic extension of KD-related vasculitis during the acute phase causes a variety of multisystem manifestations, including encephalopathy, stroke, retropharyngeal edema, pericarditis, myocarditis, KD shock syndrome, pulmonary lesions, intestinal pseudo-obstruction, gallbladder hydrops, arthritis, and myositis. These complications tend to be more common in affected children with atypical presentation. Radiologists can play an important role in the timely identification of diverse KD-associated morbidities and thus may contribute to the early diagnosis of atypical KD. Online supplemental material is available for this article. ^©RSNA, 2021.

Unexpected late-onset aortic valvulitis and moderate regurgitation during longitudinal evaluation of atypical infantile Kawasaki disease: The heart beyond coronaries!

Kawasaki disease (KD) is the most common pediatric vasculitis with coronary involvement feared as the most serious complication. The reported case describes a child presenting initially with atypical KD and coronary artery aneurysms. He was treated with intravenous immunoglobulin and aspirin. In spite of adequate compliance and no clinical recurrence, serial echocardiography revealed nonregression of aneurysm and new-onset moderate aortic regurgitation (AR) in the subacute phase produced by prolapse of noncoronary cusp of the aortic valve. AR without aortic root dilatation from persistent inflammation of the valve leaflets in KD is a rare phenomenon. This case demonstrates unusual cardiac manifestations of KD and reoriented our protocol for long-term surveillance in infantile KD.

Predictive Value of the Systemic Immune-Inflammation Index for Intravenous Immunoglobulin Resistance and Cardiovascular Complications in Kawasaki Disease

Background: The prediction of intravenous immunoglobulin (IVIG) resistance and cardiovascular complications are critically clinical issues in Kawasaki disease (KD). This prospective study firstly aimed to determine the predictive ability of the systemic immune inflammation index (SII) for IVIG resistance and cardiovascular complications and compare the prognostic accuracy of SII with that of neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR).

Methods: Patients with KD were divided into different groups according to the presence of IVIG resistance or cardiovascular complications (coronary artery lesions, valve regurgitation, myocarditis, pericardial effusion, and Kawasaki disease shock syndrome [KDSS]). The clinical and laboratory parameters were compared. Further analysis stratified by platelet level was performed. Multivariate logistic regression analysis was used to identify predictors for IVIG resistance and cardiovascular complications. The receiver operating characteristic (ROC) curve was applied to assess and compare the ability of SII, NLR, and PLR for predicting IVIG resistance and cardiovascular complications.

Results: SII was significantly higher in KD patients with IVIG-resistance, myocarditis, valve regurgitation, and KDSS. It was identified as an independent risk factor for IVIG resistance, myocarditis, and valve regurgitation. For KD patients with thrombocytopenia, there were no significant differences in SII between KD patients with IVIG resistance/cardiovascular complications and those without. The best cutoff values of SII for IVIG resistance, myocarditis, valve regurgitation, and KDSS prediction in the whole cohort were 1331.4 × 10⁹, 1368.6 × 10⁹, 1002.4 × 10⁹, and 1485.4 × 10⁹, with a corresponding sensitivity of 0.525, 0.614, 0.754, and 0.670, a specificity of 0.711, 0.723, 0.584, and 0.730, respectively. The predictive value of SII for both IVIG resistance and cardiovascular complications were not superior to that of NLR.

Conclusion: Although the parameter of SII may predict IVIG resistance, myocarditis, valve regurgitation, and KDSS in KD as a single parameter, its predictive ability was not good enough and not superior to NLR. SII might not be applicable in patients with KD having thrombocytopenia.

Multimodality cardiac evaluation in children and young adults with multisystem inflammation associated with COVID-19

Aims

Following the peak of the UK COVID-19 epidemic, a new multisystem inflammatory condition with significant cardiovascular effects emerged in young people. We utilized multimodality imaging to provide a detailed sequential description of the cardiac involvement.

Methods and Results

Twenty consecutive patients (mean age 10.6 ± 3.8 years) presenting to our institution underwent serial echocardiographic evaluation on admission (median day 5 of illness), the day coinciding with worst cardiac function (median day 7), and the day of discharge (median day 15). We performed cardiac computed tomography (CT) to assess coronary anatomy (median day 15) and cardiac magnetic resonance imaging (CMR) to assess dysfunction (median day 20). On admission, almost all patients displayed abnormal strain and tissue Doppler indices. Three-dimensional (3D) echocardiographic ejection fraction (EF) was <55% in half of the patients. Valvular regurgitation (75%) and small pericardial effusions (10%) were detected. Serial echocardiography demonstrated that the mean 3D EF deteriorated (54.7 ± 8.3% vs. 46.4 ± 8.6%, P = 0.017) before improving at discharge (P = 0.008). Left main coronary artery (LMCA) dimensions were significantly larger at discharge than at admission (Z score –0.11 ± 0.87 vs. 0.78 ± 1.23, P = 0.007). CT showed uniform coronary artery dilatation commonly affecting the LMCA (9/12). CMR detected abnormal strain in all patients with global dysfunction (EF <55%) in 35%, myocardial oedema in 50%, and subendocardial infarct in 5% (1/20) patients.

Conclusions

Pancarditis with cardiac dysfunction is common and associated with myocardial oedema. Patients require close monitoring due to coronary artery dilatation and the risk of thrombotic myocardial infarction.

Getting to the Heart of the Matter: Myocardial Injury, Coagulopathy, and Other Potential Cardiovascular Implications of COVID-19

COVID-19 was primarily identified as a respiratory illness, but reports of patients presenting initially with cardiovascular complaints are rapidly emerging. Many patients also develop cardiovascular complications during and after COVID-19 infection. Underlying cardiovascular disease increases the severity of COVID-19 infection; however, it is unclear if COVID-19 increases the risk of or causes cardiovascular complications in patients without preexisting cardiovascular disease. The review is aimed at informing the primary care physicians of the potential cardiovascular complications, especially in patients without underlying cardiovascular disease. A comprehensive literature review was performed on cardiac and vascular complications of COVID-19. The primary cardiac and vascular complications include myocarditis, acute coronary syndrome, myocardial injury, arrhythmia, heart failure, shock, multisystem inflammatory syndrome, venous and arterial thrombotic events, stroke, and coagulopathy. A detailed analysis of the pathogenesis revealed six possible mechanisms: direct cardiac damage, hypoxia-induced injury, inflammation, a dysfunctional endothelial response, coagulopathy, and the catecholamine stress response. Autopsy reports from studies show cardiomegaly, hypertrophy, ventricular dilation, infarction, and fibrosis. A wide range of cardiac and vascular complications should be considered when treating patients with confirmed or suspected COVID-19 infection. Elevated troponin and natriuretic peptides indicate an early cardiac involvement in COVID-19. Continuous monitoring of coagulation by measuring serum D-dimer can potentially prevent vascular complications. A long-term screening protocol to follow-up the patients in the primary care settings is needed to follow-up with the patients who recovered from COVID cardiovascular complications.

Pericardial Effusion in Children Admitted With Kawasaki Disease: A Multicenter Retrospective Cohort Study From the Pediatric Health Information System

Pericardial effusion (PCE) can be associated with Kawasaki disease (KD). We performed a multicenter, retrospective cohort study of the Pediatric Health Information System of children admitted with KD to determine the association between PCE and adverse outcomes. A total of 17 422 patients were in the cohort, of which 440 (3%) had PCE. PCE was associated with longer hospital length of stay (adjusted odds ratio [aOR] = 1.23; P < .01) and risk of readmission at 30 days (aOR = 1.42; P = .03). Black children were more likely to have a PCE (aOR = 1.54, P < .01) and longer length of stay (aOR = 1.05; P < .001). These data may support delayed discharge in children with PCE and KD in the hopes of preventing readmission. Special consideration needs to be given to how black children with KD are managed.

[Pericarditis is inflammation of the pericardium, which rheumatologists should know]

Als Perikarditis wird eine Entzündung des Herzbeutels bezeichnet, die mit einem Perikarderguss oder einer entzündlichen Reaktion des Myokards (Perimyokarditis) einhergehen kann. Die Perikarditis kann im Rahmen von entzündlich rheumatischen Systemerkrankungen oder als eigenständige Erkrankung vorkommen. Rezidivierende Perikarditisepisoden ohne fassbare Ursache werden als idiopathische rekurrierende Perikarditis (IRP) bezeichnet, welche wesentliche Gemeinsamkeiten mit autoinflammatorischen Erkrankungen aufweist. Der Artikel gibt einen Überblick über die Häufigkeit des Auftretens einer Perikarditis bei rheumatologischen Erkrankungen. Weiterhin werden Klinik und Pathophysiologie der IRP diskutiert. Abschließend wird die Therapie der akuten und idiopathischen Perikarditis erläutert.

Cardiac magnetic resonance feature tracking of the right ventricle in convalescent Kawasaki disease in a large single center

Background

The changes in right ventricular (RV) contractility of Kawasaki disease (KD) still remain unclear.

Hypothesis

We aimed to determine whether RV systolic dysfunction can be detected by cardiac magnetic resonance (CMR) feature tracking and to find its association with coronary artery lesions (aneurysm, thrombosis and stenosis).

Methods

Peak systolic myocardial longitudinal, radial and circumferential strain and the strain rate (RVSL, RVSR, RVSC, RVSRL, RVSRR and RVSRC) in the global RV and three levels (basal, middle and apical) were measured in 66 patients with convalescent KD. A total of 20 controls were included. Comparisons were made with controls and among KD subgroups divided with coronary artery lesions.

Results

RVSC (−10.575% vs. −10.760%), RVSL (−18.150% vs. −18.712%) and RVSRC (−0.815/s vs. −0.924/s) were slightly lower in KD group without significant difference. All the strain and strain rate presented lowest in the basal level. In subgroup comparison, lower RVSL and RVSRL were observed in the giant coronary artery aneurysm (CAA) group; RVSR (15.844% vs. 16.897%), RVSRR (1.245/s vs. 1.322/s) and RVSRC (−0.715/s vs. −0.895/s) were lower in thrombosed group; RVSRL (−1.27/s vs. −1.503/s) were lower in stenosis group. All the comparison in subgroups did not reach significant difference. From the analysis of receiver operating characteristic curve, RVSRL had a better ability to identify KD with giant CAA and stenosis. For the identification of thrombosis, RVSRC had a better ability.

Conclusions

Lower strain and strain rates of RV were detected in convalescent KD. More pronounced in those with persisting coronary artery lesions.

Acute Cardiovascular Manifestations in 286 Children With Multisystem Inflammatory Syndrome Associated With COVID-19 Infection in Europe

BACKGROUND

The aim of the study was to document cardiovascular clinical findings, cardiac imaging, and laboratory markers in children presenting with the novel multisystem inflammatory syndrome associated with coronavirus disease 2019 (COVID-19) infection.

METHODS

This real-time internet-based survey has been endorsed by the Association for European Paediatric and Congenital Cardiologists Working Groups for Cardiac Imaging and Cardiovascular Intensive Care. Children 0 to 18 years of age admitted to a hospital between February 1 and June 6, 2020, with a diagnosis of an inflammatory syndrome and acute cardiovascular complications were included.

RESULTS

<0.05). Polymerase chain reaction for severe acute respiratory syndrome coronavirus 2 was positive in 33.6%, whereas immunoglobulin M and immunoglobulin G antibodies were positive in 15.7% cases and immunoglobulin G in 43.6% cases, respectively, when checked. One child in the study cohort died.

CONCLUSIONS

Cardiac involvement is common in children with multisystem inflammatory syndrome associated with the Covid-19 pandemic. The majority of children have significantly raised levels of N-terminal pro B-type natriuretic peptide, ferritin, D-dimers, and cardiac troponin in addition to high C-reactive protein and procalcitonin levels. In comparison with adults with COVID-19, mortality in children with multisystem inflammatory syndrome associated with COVID-19 is uncommon despite multisystem involvement, very elevated inflammatory markers, and the need for intensive care support.

Non-coronary cardiac events, younger age, and IVIG unresponsiveness increase the risk for coronary aneurysms in Italian children with Kawasaki disease

OBJECTIVES

Kawasaki disease (KD) is the most frequent cause of acquired heart disease in children in high-income countries because of coronary artery involvement. Risk factors for coronary lesions can vary in consideration of different genetic background and environmental factors.

METHODS

Multicenter retrospective and prospective study including 372 consecutive children (58% boys; mean age 34.3 ± 30.3 months, Caucasian 85%) was diagnosed with KD. We divided the cohort into 2 groups according to the presence of coronary anomalies (CAA) and aneurysms. We compared the groups and studied the risk factors for CAA and for aneurysms, the most severe lesions.

RESULTS

Children with CAA were 91/372 (24.46%, aneurysms 20/372, 5.37%). Children with CAA were more likely to have a longer duration of fever (p < 0.001), later day of treatment (p < 0.001), to be IVIG non-responders and late treated (p < 0.001), while age, clinical presentation, and seasonality were not different. They also had significantly higher WBC and neutrophils, lower lymphocytes, Hb and Na during the acute stage, and slower resolution of inflammation. Age, IVIG unresponsiveness, and presence of non-coronary cardiac findings were independent risk factors for CAA and for aneurysms, while neutrophils just for CAA. Age under 6 months was a risk factor for the aneurysm. Aneurysms occurred more frequently in the first quartile of the age of KD onset (under 14 months).

CONCLUSION

Very young children with non-coronary cardiac findings are at increased risk for a more severe form of KD with aneurysms. These children could benefit from adjunctive therapy beside IVIG, especially if they have higher markers of inflammation, particularly neutrophils. Key points • Risk factors for coronary lesions can vary in consideration of different genetic background and environmental factors. • Risk factors for coronary involvement have been extensively studied in the Asian population, and others have been validated in cohorts with mixed ethnicities. • In our predominantly Caucasian population, non-coronary cardiac findings, age younger than 6 months, and IVIG unresponsiveness are independent risk factors for a more severe form of KD with aneurysms.

COVID-19 Inflammatory Syndrome With Clinical Features Resembling Kawasaki Disease

We describe 2 patients with coronavirus disease who had multiple clinical features suggestive of Kawasaki disease (KD). Both patients presented with fever lasting >5 days and were found to have rash, conjunctival injection, and swollen lips. One patient also had extremity swelling, whereas the other developed desquamation of the fingers. In both cases, laboratory results were similar to those seen in KD. These patients had highly unusual but similar features, and both appeared to respond favorably to treatment. It remains unclear whether these patients had true KD or manifestations of coronavirus disease that resembled KD.

Echocardiographic Parameters During and Beyond Onset of Kawasaki Disease Correlate with Onset Serum N-Terminal pro-Brain Natriuretic Peptide (NT-proBNP)

The N-terminal proBNP (NT-proBNP), produced by cardiomyocytes, has several reported utilities and associations in acute Kawasaki disease (KD). The objective of this study is to examine the relationship between serum values of NT-proBNP at time of KD diagnosis with cardiac systolic, diastolic function and electrocardiographic changes, at onset of the disease and during the first year of follow-up. KD was diagnosed in 127 children between March 2007 and July 2014, mean diagnostic age 3.5 ± 2.9 years. Coronary artery maximum z score was 2.6 ± 2.8 (range - 0.6 to + 18.9), with giant aneurysm in 5/122 (4.1%). Age-adjusted NT-proBNP was 2.6 ± 1.6 z score, 78/122 (63.9%) > 2.0. There was a crescendo correlation between onset NT-proBNP z score and C-Reactive protein (CRP) serum levels (slope + 0.49, p < 0.001). There was a crescendo correlation between NT-proBNP z score and indexed left ventricular (LV) mass (slope + 1.86, p = 0.02), LV diastolic function parameter E/e' ratio (slope + 0.31, p = 0.04) and a decrescendo correlation with age-adjusted LV shortening fraction (SF) (- 0.63, p = 0.02). Lower SF z score, higher left ventricular mass index and E/e' ratio were associated with higher NT-proBNP z score, but without correlation with CRP levels. Within 2-3 months from the onset of the disease, there was a resolution of the systolic dysfunction. Electrocardiographic parameter changes were associated with decreased LV shortening fraction but not with NT-proBNP. KD patients with elevated NT-proBNP at onset have sub-clinical myocardial involvement and might benefit from follow-up and continued evaluation, even in the absence of coronary artery involvement.

Kawasaki disease: pathophysiology and insights from mouse models

Kawasaki disease is an acute febrile illness and systemic vasculitis of unknown aetiology that predominantly afflicts young children, causes coronary artery aneurysms and can result in long-term cardiovascular sequelae. Kawasaki disease is the leading cause of acquired heart disease among children in the USA. Coronary artery aneurysms develop in some untreated children with Kawasaki disease, leading to ischaemic heart disease and myocardial infarction. Although intravenous immunoglobulin (IVIG) treatment reduces the risk of development of coronary artery aneurysms, some children have IVIG-resistant Kawasaki disease and are at increased risk of developing coronary artery damage. In addition, the lack of specific diagnostic tests and biomarkers for Kawasaki disease make early diagnosis and treatment challenging. The use of experimental mouse models of Kawasaki disease vasculitis has considerably improved our understanding of the pathology of the disease and helped characterize the cellular and molecular immune mechanisms contributing to cardiovascular complications, in turn leading to the development of innovative therapeutic approaches. Here, we outline the pathophysiology of Kawasaki disease and summarize and discuss the progress gained from experimental mouse models and their potential therapeutic translation to human disease.

This Review outlines the pathophysiology of Kawasaki disease and discusses the progress gained from experimental mouse models and their potential therapeutic translation to human disease.

Kawasaki disease is a childhood systemic vasculitis leading to the development of coronary artery aneurysms; it is the leading cause of acquired heart disease in children in developed countries.

The cause of Kawasaki disease is unknown, although it is suspected to be triggered by an unidentified infectious pathogen in genetically predisposed children.

Kawasaki disease might not be a normal immune response to an unusual environmental stimulus, but rather a genetically determined unusual and uncontrolled immune response to a common stimulus.

Although the aetiological agent in humans is unknown, mouse models of Kawasaki disease vasculitis demonstrate similar pathological features and have substantially accelerated discoveries in the field.

Genetic and transcriptomic analysis of blood samples from patients with Kawasaki disease and experimental evidence generated using mouse models have demonstrated the critical role of IL-1β in the pathogenesis of this disease and the therapeutic potential of targeting this pathway (currently under investigation in clinical trials).

Clinical observation of noncoronary cardiac abnormalities in Chinese children with Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is an acute, self-limited vasculitis. Coronary artery aneurysm (CAA) serves as a major contributor to the long-term prognosis of KD. In addition, acute KD usually also leads to several kinds of noncoronary cardiac abnormalities (NCA) involving the pericardium, myocardium and endocardium.

MATERIALS AND METHODS

A total of 142 Chinese children with KD were recruited from July 2015 to April 2018. Blood samples were collected at 24 hours pre-intravenous immunoglobulin (IVIG) therapy. Several inflammatory mediators and biomarkers for acute myocardial infarction were detected. Echocardiography and electrocardiography (ECG) were performed.

RESULTS

Plasma white blood cell counts (WBC) were significantly increased in patients with IVIG-nonresponsive KD when compared with their IVIG-responsive counterparts. A total of 106 children (74.65%) suffered from NCA, including 8 patients (5.63%) with pericardial effusion, 23 patients (16.20%) with acute myocarditis, 101 patients (71.13%) with valvular regurgitation and 8 patients (5.63%) with abnormal ECG. No significant differences were observed in the distribution of clinical classification and the response to IVIG therapy regardless of NCA exhibited or not.

CONCLUSIONS

Noncoronary cardiac abnormalities is almost universal in acute KD and mainly manifests as valvular regurgitation. However, it has no influence on clinical classification and the response to IVIG therapy.

Cardiac Valvular Lesions due to Kawasaki Disease: A Japanese Nationwide Survey

OBJECTIVES

To clarify the characteristics of valvular lesions after Kawasaki disease with a Japanese nationwide survey.

STUDY DESIGN

Among 137 026 patients in the nationwide Japanese surveys between 2007 and 2016, 290 (0.2%) with valvular sequelae were investigated by questionnaires.

RESULTS

Among the 290 patients with valvular sequelae, mitral regurgitation (MR), tricuspid regurgitation, aortic regurgitation, and pulmonary regurgitation were present 1 month after the development of Kawasaki disease in 183 (63%), 112 (39%), 39 (13%), and 49 (17%) patients, respectively. The numbers of patients with MR during the acute phase and 1 year after developing Kawasaki disease were 208 (72%) and 95 (33%), respectively. MR improved significantly during the late period (P < .0001). Although aortic regurgitation and tricuspid regurgitation also improved significantly (P < .001), pulmonary regurgitation did not change. Ruptured mitral valves chordae tendineae occurred in 6 infants by 6 months of age, within 4 months after the onset of Kawasaki disease. Three patients needed mitral valve plasty, and 1 patient died of acute heart failure. Another 4-month-old girl died of an acute myocardial infarction with MR. In the acute phase, there was a significant difference in the MR severity between the intravenous immunoglobulin-responder group and the intravenous immunoglobulin-resistant group (P < .05).

CONCLUSIONS

The inflammation caused by acute Kawasaki disease affects the function of the mitral valves. Most cases of MR improve with the alleviation of inflammation. Severe MR may have decreased with the development of treatment for acute vasculitis. However, ruptured mitral valves chordae tendineae rarely occurs in infants younger than 6 months old, within 4 months after Kawasaki disease.

Cardiovascular Involvement in Kawasaki Disease Is Much More Than Mere Coronary Arteritis

Kawasaki disease (KD) is now a common cause of acquired heart disease in children. Coronary artery involvement is the most serious complication in children with KD. Several non-coronary complications have now been identified in this condition but these are often overlooked. Myocarditis is an integral component of KD and may be more common than coronary artery abnormalities. Pericardial involvement and valvular abnormalities have also been observed in patients with KD. KD shock syndrome is now being increasingly recognized and may be difficult to differentiate clinically from toxic shock syndrome. Endothelial dysfunction has been reported both during acute stage and also on follow-up. This may be a potentially modifiable cardiovascular risk factor.

Kawasaki Disease Features and Myocarditis in a Patient with COVID-19

A 10-year-old male with prolonged fever, rash, and conjunctivitis presented to the emergency department with concern for Kawasaki disease, found to have myocarditis and PCR positive for SARS-CoV-2.

A Nomogram Model Identifies Eosinophilic Frequencies to Powerfully Discriminate Kawasaki Disease From Febrile Infections

Background: Kawasaki disease (KD) is a form of systemic vasculitis that occurs primarily in children under the age of 5 years old. No single laboratory data can currently distinguish KD from other febrile infection diseases. The purpose of this study was to establish a laboratory data model that can differentiate between KD and other febrile diseases caused by an infection in order to prevent coronary artery complications in KD. Methods: This study consisted of a total of 800 children (249 KD and 551 age- and gender-matched non-KD febrile infection illness) as a case-control study. Laboratory findings were analyzed using univariable, multivariable logistic regression, and nomogram models. Results: We selected 562 children at random as the model group and 238 as the validation group. The predictive nomogram included high eosinophil percentage (100 points), high C-reactive protein (93 points), high alanine transaminase (84 points), low albumin (79 points), and high white blood cell (64 points), which generated an area under the curve of 0.873 for the model group and 0.905 for the validation group. Eosinophilia showed the highest OR: 5.015 (95% CI:-3.068-8.197) during multiple logistic regression. The sensitivity and specificity in the validation group were 84.1 and 86%, respectively. The calibration curves of the validation group for the probability of KD showed near an agreement to the actual probability. Conclusion: Eosinophilia is a major factor in this nomogram model and had high precision for predicting KD. This report is the first among the existing literature to demonstrate the important role of eosinophil in KD by nomogram.

Atypical manifestations of cardiomegaly and nephrotic syndrome in Kawasaki disease: Two case reports

RATIONALE

To examine atypical manifestations of Kawasaki disease (KD) in children.

BACKGROUND

Cardiovascular complications during acute KD are a major contributor to its mortality rate. It can involve the pericardium, the myocardium, the endocardium, and/or the coronary arteries; however, cardiomegaly and nephrotic syndrome (NS) during the acute stage of KD have seldom been reported.

PATIENT CONCERNS

Two children, each with a fever lasting more than 5 days, were diagnosed with cardiomegaly using echocardiography in the early phase of Kawasaki disease (within 2 weeks). Case 1 was misdiagnosed with NS because of the proteinuria, hypoalbuminemia, and edema present at the onset of the disease.

DIAGNOSES

A diagnosis of incomplete KD was based on a constellation of clinical manifestations and symptoms and was supported by laboratory results.

INTERVENTIONS

Intravenous immunoglobulin (IVIG) and aspirin were administered, supplemented with and without supplemental steroid therapy (case dependent).

OUTCOMES

The clinical manifestations and syndromes of the two cases were completely resolved and their heart size restored to normal within 2 weeks, with no evidence of coronary artery lesions (CAL).

MAIN LESSONS

Physical findings and manifestations are atypical in incomplete KD. Cardiomegaly and nephrotic syndrome can be an early manifestation of KD; cardiomegaly, especially, should be recognized as a possible manifestation of the acute stage of KD. Furthermore, these symptoms can be rapidly relieved by treatment with IVIG, with or without supplemental steroid therapy.

Refractory Kawasaki disease: diagnostic and management challenges

Kawasaki disease (KD), an acute, self-limiting, medium-sized arterial vasculitis, is now the most common cause of acquired heart disease in childhood in the developed world. In this review, we discuss the diagnosis of KD, predicting resistance to traditional therapy and treatment options in refractory or high-risk disease. We also highlight ongoing clinical trials and other potential avenues of research which may prove beneficial in managing children, especially those with resistant KD.

IL-1 receptor antagonist, anakinra, prevents myocardial dysfunction in a mouse model of Kawasaki disease vasculitis and myocarditis

Kawasaki disease (KD) vasculitis is an acute febrile illness of childhood characterized by systemic vasculitis of unknown origin, and is the most common cause of acquired heart disease among children in the United States. While  histological evidence of myocarditis can be found in all patients with acute KD, only a minority of patients are clinically symptomatic and a subset demonstrate echocardiographic evidence of impaired myocardial function, as well as increased left ventricular mass, presumed to be due to myocardial edema and inflammation. Up to a third of KD patients fail to respond to first-line therapy with intravenous immunoglobulin (IVIG), and the use of interleukin (IL)-1 receptor antagonist (IL-1Ra, anakinra) is currently being investigated as an alternative therapeutic approach to treat IVIG-resistant patients. In this study, we sought to investigate the effect of IL-1Ra on myocardial dysfunction and its relation to myocarditis development during KD vasculitis. We used the Lactobacillus casei cell-wall extract (LCWE)-induced murine model of KD vasculitis and investigated the effect of IL-1Ra pretreatment on myocardial dysfunction during KD vasculitis by performing histological, magnetic resonance imaging (MRI) and echocardiographic evaluations. IL-1Ra pretreatment significantly reduced KD-induced myocardial inflammation and N-terminal pro B-type natriuretic peptide (NT-proBNP) release. Both MRI and echocardiographic studies on LCWE-injected KD mice demonstrated that IL-1Ra pretreatment results in an improved ejection fraction and a normalized left ventricular function. These findings further support the potential beneficial effects of IL-1Ra therapy in preventing the cardiovascular complications in acute KD patients, including the myocarditis and myocardial dysfunction associated with acute KD.

Evaluation of left ventricular function in immunoglobulin-resistant children with Kawasaki disease: a two-dimensional speckle tracking echocardiography study

Background

Kawasaki disease (KD) patients who are unresponsive to intravenous immune globulin (IVIG) have a high occurrence of coronary artery lesions (CALs). The characteristics of left ventricular (LV) function alternation in IVIG‐resistant patients are not well‐described.

Hypothesis

Two‐dimensional speckle tracking echocardiography (STE) is a useful technique that can accurately detect myocardium subclinical dysfunction in resistant patients and may assist in differentiating patients with KD at a higher risk of IVIG resistance.

Methods

A consecutive sample of 50 IVIG‐resistant patients (25 males, 2.2 ± 0.9 years), 50 IVIG‐responsive patients (27 males, 2.2 ± 0.7 years) and 50 normal subjects (27 males, 2.1 ± 0.9 years) were analyzed using STE, and receiver operating characteristic curve (ROC) analysis was utilized to determine the threshold values of STE parameters associated with IVIG resistance.

Results

Compared with normal children, IVIG‐resistant patients had lower global longitudinal strain (GLS) (15.82 ± 3.32 vs 20.01 ± 2.98, P = 0.000) and lower global circumferential strain (GCS) (16.65 ± 3.12 vs 20.11 ± 2.86, P = 0.042). Both GLS and GCS in IVIG‐resistant patients were significantly lower than in IVIG‐responsive patients (15.82 ± 3.32 vs 19.95 ± 3.01, 16.65 ± 3.12 vs 19.01 ± 3.00, P = .000, .030, respectively). ROC analysis demonstrated that the absolute values of GLS < 16.8% and GCS < 15.9% were optimal predictors of IVIG unresponsiveness (area under the curve = 0.78, 0.75; sensitivity = 0.83, 0.79; specificity = 0.69, 0.65, respectively).

Conclusion

IVIG‐resistant patients presented with more severe LV systolic dysfunction compared with IVIG‐responsive patients, which may be the result of myocarditis rather than CALs. STE may be a helpful diagnostic tool that provides supportive criteria to detect KD patients at a higher risk of IVIG resistance.

High Frequency of Cardiovascular Complications in Tunisian Kawasaki Disease Patients: Need for a Further Awareness

BACKGROUND

The outcome of Kawasaki disease (KD) depends on cardiovascular complications (CVCs).

OBJECTIVES

This study aimed to explore diagnostic features and CVCs in Tunisian patients with KD.

METHODS

In total, 33 Tunisian patients (age, 2.9 ± 2.2 years) fulfilling the diagnosis criteria of KD, were retrospectively reviewed. Nonparametric tests were used to compare the two groups with regards to coronary complications (CCs).

RESULTS

Diagnosis of KD was established at day 11 ± 5.1 from the beginning of the fever. Apyrexia was obtained in an average of 29 h after completion of intravenous immunoglobulin. CVCs were identified in 52% of cases: CC in 15 patients (giant aneurysm >8 mm in five patients) and non-CCs in 6 patients (severe in three patients). CCs were more frequently associated with the male sex (p = 0.037), fever lasting >8 days (p = 0.028) and longer time to apyrexia (p = 0.031).

CONCLUSION

In Tunisia, better knowledge and monitoring of KD are warranted.

Coronary artery aneurysms are more severe in infants than in older children with Kawasaki disease

OBJECTIVE

We aimed to compare the severity of coronary artery abnormalities in Kawasaki disease between infants and older children.

METHODS

We retrospectively reviewed and compared coronary artery dilation and aneurysm severity in infants <1 year of age with Kawasaki disease at our centre over a 10-year period with that observed in children ≥1 year of age in the Pediatric Heart Network Trial of Pulse Steroid Therapy in Kawasaki Disease. Coronary artery abnormalities were defined by z-scores according to American Heart Association guidelines.

RESULTS

Of the 93 infants identified during the study period, 80 were treated with intravenous gamma globulin within the first 10 days of illness and were included for comparison to 170 children ≥1 year of age treated in the same time frame from the Pediatric Heart Network public database. The mean maximum z-score was significantly higher in infants compared with older children (3.37 vs 2.07, p<0.001). A higher incidence of medium and giant aneurysms was observed in infants compared with children ≥1 year of age (11% vs 3% for medium aneurysms, p=0.015; 8% vs <1% for giant aneurysms, p=0.005).

CONCLUSIONS

Infants with Kawasaki disease have more severe coronary artery dilation compared with older children, and a higher prevalence of medium and giant aneurysms. Because adverse outcomes are closely linked to the maximal coronary artery diameter in Kawasaki disease, patients diagnosed as infants require very close long-term monitoring for cardiac complications.

Myocardial fibrosis after adrenergic stimulation as a long-term sequela in a mouse model of Kawasaki disease vasculitis

Kawasaki disease (KD), the leading cause of acquired cardiac disease among children, is often associated with myocarditis that may lead to long-term myocardial dysfunction and fibrosis. Although those myocardial changes develop during the acute phase, they may persist for decades and closely correlate with long-term myocardial sequelae. Using the Lactobacillus casei cell wall extract-induced (LCWE-induced) KD vasculitis murine model, we investigated long-term cardiovascular sequelae, such as myocardial dysfunction, fibrosis, and coronary microvascular lesions following adrenergic stimuli after established KD vasculitis. We found that adrenergic stimulation with isoproterenol following LCWE-induced KD vasculitis in mice was associated with increased risk of cardiac hypertrophy and myocardial fibrosis, diminished ejection fraction, and increased serum levels of brain natriuretic peptide. Myocardial fibrosis resulting from pharmacologic-induced exercise after KD development was IL-1 signaling dependent and was associated with a significant reduction in myocardial capillary CD31 expression, indicative of a rarefied myocardial capillary bed. These observations suggest that adrenergic stimulation after KD vasculitis may lead to cardiac hypertrophy and bridging fibrosis in the myocardium in the LCWE-induced KD vasculitis mouse model and that this process involves IL-1 signaling and diminished microvascular circulation in the myocardium.

Extracorporeal Membrane Oxygenation Support for Cardiac Dysfunction Due to Kawasaki Disease Shock Syndrome

Background: Kawasaki disease (KD) is usually characterized as an inflammatory vasculitis during early childhood, which predominantly involves medium-sized arteries and is treated with intravenous γ-globulin (IVIG) and oral aspirin. KD with hemodynamic instability, characterized by systolic blood pressure decreasing by more than 20% below the normal range, is defined as Kawasaki disease shock syndrome (KDSS). The pathogenesis of KDSS is still not comprehensively understood. Life-threatening cardiogenic shock can occur during the acute phase of KDSS, while the mechanism of cardiac dysfunction due to KDSS is still controversial, and such cases are rarely reported. Here, we present the application of veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) for cardiac function support of a child with KDSS. By doing so, it will be a reminder that KDSS can cause severe cardiac dysfunction, and we should stay vigilant at the early stage of the disease to distinguish KDSS from toxic septic shock in the first place and initiate the appropriate treatment at the right moment, in order to prevent such patients from having irreversible outcomes.

State-of-the-art acute phase management of Kawasaki disease after 2017 scientific statement from the American Heart Association

Kawasaki disease (KD) has become the most common form of pediatric systemic vasculitis. Although patients with KD received intravenous immunoglobulin (IVIG) therapy, coronary arterial lesions (CALs) still occurred in 5%-10% of these patients during the acute stage. CALs may persist and even progress to stenosis or obstruction. Therefore, CALs following KD are currently the leading cause of acquired heart diseases in children. The etiology of CALs remains unknown despite more than four decades of research. Two unsolved problems are IVIG unresponsiveness and the diagnosis of incomplete KD. The two subgroups of KD patients with these problems have a high risk of CAL. In April 2017, the American Heart Association (AHA) updated the guidelines for the diagnosis, treatment, and long-term management of KD. Compared with the previous KD guidelines published in 2004, the new guidelines provide solutions to the aforementioned two problems and emphasize risk stratification by using coronary artery Z score systems, as well as coronary severity-based management and long-term follow-up. Therefore, in this study, we merged the AHA Scientific Statement in 2017 with recent findings for Taiwanese KD patients to provide potential future care directions for Taiwanese patients with KD.

A Decade of NT-proBNP in Acute Kawasaki Disease, from Physiological Response to Clinical Relevance

Kawasaki disease (KD) is an inflammatory febrile illness of early childhood and the primary cause of acquired heart disease during childhood. Coronary artery aneurysms (CAA) are a serious complication of KD, leading to ischemic heart disease, myocardial infarction, and sudden cardiac death. Timely diagnosis in the first ten days of fever is crucial to reduce the risk of coronary artery complications. Nitrogen-terminal B-type natriuretic peptide (NT-proBNP), originally used for the management of adults with heart disease, was shown to be useful in the diagnosis and management of patients with KD. NT-proBNP is released by cardiomyocytes in response to mechanical factors such as the dilation of cardiac chambers, and to pro-inflammatory cytokines. The utility of NT-proBNP as a biological marker in KD is based on the universal myocardial inflammatory component early in the course of the disease. Patients with KD have higher NT-proBNP at the time of diagnosis than febrile controls, with a pooled sensitivity of 89% (95% confidence interval 78–95), and a specificity of 72% (95% confidence interval 58–82). The positive likelihood ratio is 3.2:1 (95% confidence interval 2.1–4.8). Moreover, patients with resistance to intravenous immunoglobulin treatment and CAA were found to have higher levels of NT-proBNP, suggesting a prognostic role. Nevertheless, the non-specificity of NT-proBNP to KD limits its use as a stand-alone test. In this light, a tentative associative retrospective diagnostic algorithm was highly reliable for including all cases at risk of CAA, which warrants further prospective studies for a better diagnostic index of suspicion and risk stratification of patients.