Giant Coronary Aneurysm in an Infant with Multisystem Inflammatory Syndrome.

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV2), also known as COVID-19, has rapidly spread resulting in a worldwide pandemic. Although COVID-19 infections in children are generally mild and nonfatal, there is increasing recognition of its association with the multisystem inflammatory syndrome in children (MIS-C), leading to serious illness and possible long-term complications. This report describes a 6-month-old Indian infant who presented with a 4-day history of fever with nonspecific signs of viral illness and erythematous rash. Although the initial echocardiogram was normal, subsequent scans showed progressive dilatation of bilateral coronary arteries. Despite the timely intervention, he developed left coronary artery thrombosis, leading to myocardial infarction. His SARS-CoV-2 antibody titers were strongly positive. Through this case, we discuss the management of MIS-C with coronary artery involvement. The long-term outcome of coronary artery aneurysm due to MIS-C remains unknown and close follow-up is important. Further research is pivotal for a better understanding of MIS-C. Copyright:

INTRODUCTION

The COVID-19 pandemic caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has affected more than 150 million people with over 3 million deaths to date.[1] Approximately 1% of the total cases are seen in children, with the majority being either asymptomatic or having mild symptoms.[2] However, concerns have been raised about a newly emerging syndrome with severe manifestations in children. This syndrome termed multisystem inflammatory syndrome in children (MIS-C), can have a protean presentation, posing a diagnostic challenge for physicians.[3] In addition, as we await further studies, treatment remains based on limited evidence and expert consensus.

We report this case to increase familiarity among physicians regarding the management of MIS-C with coronary artery involvement.

CASE PRESENTATION

A previously healthy 6-month-old Indian boy presented with a 4-day history of fever, cough, diarrhea, bilateral red eyes, a generalized rash, and cracked lips. There was no history of recent travel or any COVID-19 contact within the 4 weeks before the onset of symptoms. On examination, he was febrile (temperature of 38.9°C), irritable with mild dehydration. His vitals showed a heart rate of 172/min, respiratory rate of 56/min, and blood pressure of 92/74 mmHg. He had cracked lips, strawberry tongue, and bilateral nonpurulent conjunctivitis. A generalized erythematous maculopapular rash was present on the trunk and extremities with minimal swelling on bilateral feet [Figures 1 and 2]. The rest of the general and systemic examination was normal. His initial investigations are shown in Table 1. Echocardiography on the day of admission was normal. Given the clinical features and laboratory results, a diagnosis of incomplete Kawasaki disease (KD) versus MIS-C was made.

Figure 1

Maculopapular erythematous rash on the trunk

Figure 2

Edema on the dorsum of the foot

Table 1

Laboratory results of the patient during the hospital stay

Intervention	Day of admission
	1 IVIG 1st	4 IVIG 2nd	6	8 Methlyprednisolone	10 Infliximab	11	12
CRP mg/L	130	202	32	132	155	66	78
Procalcitonin (ng/ml)	19.82	>50	10.87	0.97	-	-	-
Hb (g/dL)	10.1	7.6	12.2	12.4	11.1	10.2	11
TLC (×109/L)	11.26	28.32	38.73	45.85	28.78	34.86	42
Platelet (×109/L)	302	249	431	964	995	934	1131
AST (U/L)	80	31	-	-	-	-	-
Albumin (g/L)	36	27	-	-	-	-	-
ALT (U/L)	83	47	-	-	-	-	-
Ferritin (30-400 ng/ml)	182	212.7	-	-	-	-	-
Fibrinogen (200-400 mg/dL)	302	292	-	-	-	-	-
Triglycerides (<1.7 mmol/L)	1.7	1.6	-	-	-	-	-
Sodium (mmol/L)	139.00	-	136	-	138	-	-
Potassium (mmol/L)	3.82	-	4.2	-	3.9	-	-
Creatinine (mg/dL)	0.16	-	0.38	-	-	-	-
BNP (pg/ml)	824.1	1496.6	101.57	-	-	-	-
Troponin T (ng/L)	6.67	7.2	-	-	-	-	-
Upper respiratory panel				Normal
Coagulation profile				Normal
SARS-CoV-2 RT-PCR				Not detected
SARS-CoV-2 S1 antibody (normal<0.79)				11 U/ml
Blood culture				No growth
Urine culture				No growth

CRP: C-reactive protein, IVIG: Intravenous immunoglobulin, SARS-CoV-2: Severe acute respiratory syndrome-coronavirus-2, RT - PCR - Reverse transcription - polymerase chain reaction; Hb – Haemoglobin; TLC - Total leucocyte count; AST - Aspartate aminotransferase; ALT - Alanine aminotransferase; BNP - Brain natriuretic peptide

Intravenous immunoglobulin (IVIG) (2 gm/kg) and high-dose aspirin were administered on the 1st day of admission. Given the COVID-19 pandemic situation, awaiting COVID antibody results, he was also commenced on methylprednisolone (2 mg/kg/day). Over the next 36 h, the child continued to have fever spikes with an increase in C-reactive protein (CRP). Hence, the second dose of IVIG was administered on the 4th day of admission. After the second dose, the child became afebrile with improvement in the inflammatory markers.

However, on the 8th day of admission, he again started having fever spikes with a further elevation of CRP. Repeat echocardiography showed bilateral dilated coronary arteries, with the right coronary artery (RCA) and left coronary artery (LCA) diameter increased to 4.5 mm and 3.5 mm, respectively. Hence, pulse methylprednisolone, enoxaparin, and clopidogrel were initiated after a discussion with the pediatric rheumatologist. A high-dose aspirin was continued. The next day, echocardiography showed an RCA of 4.8 mm, LCA of 4.5 mm, and the left anterior descending artery of 6.7 mm with normal cardiac function. The child became afebrile on the 10th day but the CRP remained high. Hence, given the elevated CRP and increasing coronary dilatation, a single dose of infliximab was administered. However, echocardiography on the 11th day showed progressive dilation of the RCA to 6 mm and the LCA to 10 mm. Given the echocardiography findings and persistently elevated CRP, he was referred to a higher center for possible plasmapheresis and further management.

On the day of transfer, he developed increasing irritability and refusal to feed. A repeat echocardiogram showed a large thrombus completely occluding the LCA aneurysm with severe cardiac dysfunction [Figure 3]. Unfortunately, the infant suffered cardiac arrest and was successfully resuscitated and placed on extracorporeal mechanical oxygenation (ECMO). He was successfully weaned from ECMO 2 weeks later but developed chronic renal failure and neurological insult. SARS-CoV-2 S1 antibody titers were strongly positive (11 U/ml [normal <0.79]).

Figure 3

Parasternal short-axis view showing large thrombus completely occluding the left coronary artery aneurysm

DISCUSSION

Although MIS-C affects multiple organ systems, cardiovascular involvement is worrisome. Cardiac manifestations are seen in around 80% of cases of MIS-C and include ventricular dysfunction, coronary artery dilation, coronary artery aneurysm (CAA), arrhythmia, conduction abnormalities, pericarditis, valvulitis, and cardiogenic shock.[45] Coronary artery involvement in MIS-C ranges from transient mild dilatation to giant CAA, with an incidence of 6%–24%.[4] It can be seen at presentation or develop during hospitalization or follow-up. Various hypotheses put forth for coronary involvement in MIS-C include circulating inflammatory mediators, disruption of the arterial wall, and immune-mediated vasculitis.[5] Giant CAAs (>8 mm) have a high chance of rupture with up to half of the cases developing thrombosis, resulting in myocardial infarction, dysrhythmias, or sudden death.[6] Hence, early aggressive management is warranted in such cases.

However, as seen in our patient, despite timely intervention, CAA may still develop. To date, there are no studies to identify the patients at high risk for the development of CAA in MIS-C.

The management of MIS-C with coronary involvement has been largely based on expert opinion and extrapolated from the treatment of KD, adult experience with COVID-19, and other systemic inflammatory disorders in children. Management aims to reduce the systemic inflammation, thereby preventing further coronary dilatation, thrombus formation, and rupture of the aneurysm.[78] A stepwise progression of immunomodulatory therapies is recommended for the reduction of systemic inflammation. IVIG at a dose of 2 g/kg is the first-line therapy for all children, with a consideration for a repeat dose in case of a poor or partial response.[78] Resistance to IVIG is high and can be seen in 50%–60% of the cases of MIS-C.[9] Children who remain unwell with pyrexia after 24 h of IVIG are candidates for the second-line therapy with intravenous methylprednisolone. Some guidelines have advocated the initial use of methylprednisolone alongside IVIG, especially in those with coronary artery changes.[78] Ouldali et al. observed that combined treatment with IVIG and methylprednisolone was associated with a more favorable fever course and less severe acute complications.[9] The use of biologic drugs (tocilizumab, anakinra, and infliximab) should be considered a third-line option in severe illness if there is no response to the above treatments.[78] The choice of the biological agent should be made by the multidisciplinary team based on their experience. There is a high risk of thrombosis in MIS-C due to the presence of thrombocytosis, increased platelet adhesion, inflammation, and endothelial dysfunction, together with abnormal flow conditions through areas of severe dilation.[578]

Patients having coronary artery z-score of 2.5–10.0 should be started on low-dose aspirin. Systemic anticoagulation with enoxaparin or warfarin should be added when the z-score is >10.0. As seen with KD, failure to timely escalate thromboprophylaxis in CAA can result in thrombosis, leading to myocardial ischemia/infarction. In infants, similar to our case, these events are either silent or associated with nonspecific symptoms, such as unusual fussiness, vomiting, ECG changes, or shock.[10] Supportive measures such as sedative drugs, calcium-channel blockers, and beta-blockers can help in lowering blood pressure and heart rate, thereby reducing stress on the dilated coronary arterial wall. The frequency of echocardiography in the acute phase is determined by the cardiologist based on previous echocardiography findings, the clinical status of the patient, and changes in inflammatory markers.

The prognosis and natural history of coronary dilatation associated with MIS-C are unknown at present. Although it often improves and/or normalizes before discharge, some patients have continuous progression following discharge.[78] Hence, it is recommended to follow-up for at least a year after the initial diagnosis. Low-dose aspirin should be continued for at least 6 weeks. Anticoagulation should be continued indefinitely in CAA with a z-score of >10 and for at least 3 months in documented thrombosis (pending thrombus resolution).[7]

CONCLUSION

MIS-C is a rare but severe complication associated with COVID-19 infection in children. A multidisciplinary team, including a cardiologist, hematologist, infectious disease, rheumatologist, and intensivist should be involved in the management. Further research and long-term follow-up studies are pivotal for a better understanding of MIS-C.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given their consent for the child's images and other clinical information to be reported in the journal. The guardian understands that patient names and initials will not be published and due efforts will be made to conceal patient identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.