Cardiac Manifestations of Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with SARS-CoV-2 Infection


avatar Alireza Ghodsi ORCID 1 , avatar Elnaz Mahmoudabadi 1 , avatar Sara Ghahremani ORCID 2 , avatar Abdolreza Malek ORCID 2 , *

Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Department of Pediatrics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

how to cite: Ghodsi A, Mahmoudabadi E, Ghahremani S, Malek A. Cardiac Manifestations of Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with SARS-CoV-2 Infection. Arch Pediatr Infect Dis. 2021;9(4):e109915.



Multisystem inflammatory syndrome in children (MIS-C) is an emerging condition after the spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, termed COVID-19. This study aimed to describe the cardiac manifestations of children diagnosed with MIS-C.

Evidence Acquisition:

This narrative review was conducted by searching the PubMed, Scopus, and Google Scholar databases to review MIS-C cardiac manifestations up to September 30, 2020. The demographic features, past medical history, clinical signs and symptoms, cardiac involvement, and the type of COVID-19 diagnosis confirmation were extracted.


In many children, MIS-C seems to be a post-infectious complication of the COVID-19 infection. This syndrome affects multiple organs and has various clinical manifestations mimicking Kawasaki disease. Patients frequently present with persistent fever, kidney injury, gastrointestinal (GI) problems, neurologic symptoms, mucosal changes, conjunctivitis, and cardiac involvement. Children with MIS are more likely to present with hypotension, shock, and cardiac dysfunction, rather than coronary artery abnormalities and arrhythmia. Children with MIS need close observation; some need to be hospitalized, and a few may need a Pediatric Intensive Care Unit (PICU) admission. Treatment currently includes anticoagulants, IV immunoglobulin, and anti-inflammatory drugs.


As a novel syndrome associated with SARS-CoV-2 infection, MIS-C is potentially lethal. Cardiac manifestations, including coronary and myocardial involvement, are common and should be carefully identified. With prompt diagnosis and proper treatment, most children will survive, but the outcomes of the disease are unknown, so long-term follow-ups are required.

1. Context

The SARS-CoV-2 infection, termed COVID-19, has spread very quickly and affected all ages, even newborns (1, 2). Initially, there was a misconception among the researchers believing that the virus does not affect children. However, it was then proposed that children are usually asymptomatic or present mild symptoms, but a complete immunity cannot be proposed for this age group (3). Since late April 2020, multiple studies from Europe and the United States showed that 2% - 6% of SARS-CoV-2-infected children exhibited a severe multi-system inflammatory syndrome with similarities to Kawasaki disease (4-6).

As there is no comprehensive testing, the true incidence of this severe condition in pediatrics has remained unclear. This significant hyper-inflammatory response can cause cardiovascular disorders, and some of these children may deteriorate faster and need admission to the Pediatric Intensive Care Unit (PICU) due to cardiogenic shock or acute left ventricular dysfunction (7). Apart from cardiac manifestations, various clinical symptoms have also been reported, including neurological, renal, significant gastrointestinal (GI), and mild respiratory symptoms, as well as rashes and stomatitis (8). Although it is still not fully understood whether this multisystem inflammatory syndrome in children (MIS-C) is a primary complication of COVID-19 infection or a post-infectious complication, a correlation is highly suggestive based on epidemiologic data (7).

There is little information about the cardiac involvement associated with COVID-19 in pediatric cases, and most of the studies on cardiac involvement are case reports or case series. It is also possible that children with an underlying cardiac disease are at a higher risk of experiencing severe cardiac complications following the COVID-19 infection (9). Reports on MIS-C have shown coronary artery involvement, myocarditis, ventricular dysfunction, hemodynamic instability, and PICU admission, all of which suggest that cardiac dysfunction might be a notable risk factor for severe SARS-CoV-2 infection in pediatrics (10). Therefore, a literature review in this regard would be beneficial. This study aimed to review and summarize the available evidence on the potential cardiac clinical presentations in children with MIS to give a better perspective on management and care for these patients.

It should be noted that different terms have been used to refer to this novel condition, such as multisystem inflammatory syndrome in children (MIS-C), hyper-inflammatory shock in children with COVID-19, “Coronasacki”, “Kawashocky”, Pediatric COVID-19-associated inflammatory disorder (PCAID), and pediatric multisystem inflammatory syndrome (PMIS) (7). In this review article, we continue to use the term MIS-C.

2. Methods

A literature review was conducted by searching PubMed, Scopus, and Google Scholar. The following keywords were used for the search: “Pediatrics”, “children”, “heart”, “cardiac”, “Coronavirus disease-19”, “COVID19”, “SARS-CoV-2”, “systemic inflammatory response syndrome”, “multisystem inflammatory disorder in children and adolescents”, “MISC”, “PMIS”, “PCAID”, “Coronasacki”, and “Kawashocky”. We included case reports and case series related to MIS-C associated with SARS-CoV-2 infection. The inclusion criterion was defined as being a case report or case series reporting some findings of cardiac involvement in pediatrics with COVID-19. Articles published in languages other than English and those irrelevant to our objectives, like commentaries, other reviews, and letters to editors, were excluded. The last search was performed on September 30, 2020. We used the Newcastle-Ottawa scale (NOS) (11) for the quality assessment of the studies, and those with top quality were enrolled. The baseline data including the first author’s name of the article, number of cases, age, sex, past medical history, ethnicity, clinical signs and symptoms, and the type of COVID-19 diagnosis confirmation (PCR or serology) were extracted. Moreover, the laboratory, electrocardiography, and echocardiography findings were gathered.

3. Definition of MIS-C

The three definitions of MIS-C, by the World Health Organization (WHO) (12), the Centers for disease control and prevention (CDC) (13), and the Royal College of Pediatrics and Child Health (RCPCH) (14), are presented in Table 1. The presence of fever, multisystem organ involvement without alternative plausible diagnoses, laboratory evidence of inflammation, and recent exposure to a COVID-19 case or evidence of COVID-19 infection are the key elements in all MIS-C cases. But, some signs, including fever duration and organ involvement, vary among these criteria.

Table 1.

Case Definition of Multisystem Inflammatory Syndrome in Children

WHOCDCNHS-the Royal College of Pediatrics and Child Health
Age (years)0 - 19< 21Children
FeverFever ≥ 3 daysSubjective persistent fever ≥ 24 hours or documented fever > 38.0°C for ≥ 24 hoursPersistent fever > 38.5°C
Clinical findings Mucocutaneous inflammation signs (e.g., stomatitis), bilateral non-purulent conjunctivitis or rash, shock or hypotension, ventricular dysfunction, valvulitis, pericarditis, or coronary involvement (including an increased level of NT-proBNP /troponin or echo findings), acute GI manifestations, including abdominal pain, diarrhea, or vomiting Evidence of clinical deterioration requiring hospital admission, in addition to multiple (≥ 2) organ dysfunction (renal, dermatologic, cardiovascular, respiratory, GI, hematologic, or neurologic)Single or multi-organ dysfunction (cardiovascular, respiratory, renal, GI, hematologic, dermatologic, or neurologic). Oxygen requirement and hypotension have been reported in most kids. Other features, including abdominal pain, diarrhea, vomiting, conjunctivitis, rash, sore throat, cough, respiratory symptoms, headache, confusion, lymphadenopathy, stomatitis, neck swelling, hands and feet edema, syncope have been seen in some children.
Laboratory findingsElevated inflammatory factors (e.g., CRP, ESR, or procalcitonin) evidence of coagulopathy in laboratory data (PT, PTT, INR, and D-dimer)Elevated ESR, CRP, LDH, procalcitonin, fibrinogen, D-dimer, ferritin, IL-6, hypoalbuminemia neutrophilia; lymphocytopeniaAbnormal fibrinogen level, hypoalbuminemia, high D-dimer and ferritin amount Some: acute kidney injury, anemia, coagulopathy, thrombocytopenia, elevated IL-6, elevated IL-10, hypertransaminasemia, proteinuria, high troponin, increased creatine kinase level, elevated triglycerides, high LDH
Evidence of COVID-19 infection Positive for SARS-CoV-2 infection by serology, antigen test, or RT-PCR or exposure to patients with COVID-19 infectionRT-PCR, or antigen test, or serology positive for COVID-19 or possible contact with COVID-19 patients within a month before to the initiation of clinical featuresSARS-CoV-2 RT-PCR testing may be positive or negative
Exclusion of other microbial causesExclusion of any other infectious causes of inflammation, including toxic shock syndrome, bacterial sepsis, staphylococcal or streptococcal infectionsExclusion of alternative plausible diagnosesExclusion of any other microbial cause, including infectious myocarditis, bacterial sepsis, and staphylococcal/streptococcal toxic shock syndromes
Additional commentsMIS-C must be considered in children with characteristics of toxic shock syndrome or typical or atypical Kawasaki disease Consider MIS-C in any pediatric death with evidence of COVID-19 infection. It should be considered in children with features of typical or atypical Kawasaki disease who meet the case definition for MIS-CChildren may fulfill full or partial criteria for Kawasaki disease

4. Clinical Manifestation

The available information regarding the syndrome shows that the age of patients ranged from two months to 20 years, and the majority of cases were previously healthy (15, 16). Almost all affected children had a persistent fever for ≥ 4 days and GI symptoms, including abdominal pain, diarrhea, and vomit. Other common clinical manifestations were mucocutaneous changes resembling Kawasaki disease (skin rash and conjunctivitis), extremity edema, lymphadenopathy, headache, mild respiratory distress, myalgia, fatigue, and cardiac symptoms (Table 2). Some patients presented with shock and hypotension requiring PICU admission (17, 18). The cardiac findings in MIS-C patients are divergent from Kawasaki disease’s manifestations. Children with this syndrome were more likely to present with hypotension, shock, and cardiac dysfunction, rather than coronary artery abnormalities (Figure 1) (19).

Table 2.

Demographics, Clinical Manifestations, and Cardiac Involvement in Reports of Children WITH Multisystem Inflammatory Syndrome

AuthorNumber of CasesAge, ySexPast Medical HistoryEthnicitySymptoms Cardiac InvolvementSARS-CoV-2 Test
Coronary InvolvementVentricular FunctionArrhythmia/ECG ChangesTroponinProBNP/BNPRT-PCRSerology
Belhadjer et al. (20)351 - 1618 M, 17 FPreviously healthy (31); asthma (3); SLE (1); overweight (BMI > 25) (6)-Fever (35); GI symptoms (29); asthenia (35); respiratory distress (23); rash (20); lymphadenopathy (21); meningism (11); chest pain (6; cardiogenic shock (28); pericardial effusion (3)Mild coronary dilatation (z score > 2) (6/35); no aneurysmsLVEF < 30% (10); LVEF: 30 to 50% (25); LVEF < 50% (inclusion criteria) (35); takotsubo (1); segmental wall; hypokinesis (3); global LV hypokinesis (31)Ventricular arrhythmia (1) ST elevation at onset (1)Elevated (mild to moderate)Elevated proBNP or BNP (35)14 cases were positive30/35: IgG+ (28); IgM+ (2)
Toubiana et al. (21)214 - 179 M, 12 F-African ancestry (12)Fever (21); GI symptoms (21); rash (16); conjunctivitis (17); hypotension/shock (17); lips and oral cavity changes (16); changes to extremities (10); serous effusion (12); irritability (12) cervical lymphadenopathy (12); neurological features (6)Dilated coronary arteries (z-score 2 - 2.5) (5) echo-bright coronary arteries (3)Myocarditis (16)Increased QT interval (2) diffuse ST elevation or ventricular dysrhythmiasElevated (17)Elevated (14/18)8 cases were positiveIgG+ (19)
Cheung et al. (22)172 - 1611 M, 4 FMild asthma (3)Ashkenazi; Jewish (6); Black (4); White (6); Asian (1)Fever (17); skin rash (12); GI symptoms (15); conjunctivitis (11); mucosal changes (9); neurological problems (8); respiratory (7); shock (13); myalgia (5); cervical lymphadenopathy (6); skin desquamation (3)Echobright coronaries (7) medium-sized aneurysm (z-score 2.5) (1)Normal-mild LV; dysfunction (11); moderate-severe; LV dysfunction (6)Non-specific ST/T-wave abnormalities (10) Attenuated QRS voltage (1)Elevated (14)Elevated (15)8 cases were positiveIgM/IgG + (9)
Whittaker et al. (18)586 - 1425 M, 33 FComorbid (7): asthma (3); alopecia (1); sickle cell trait (1); epilepsy (1); neuro-disability (1)White (12); Black (22); Asian (18); other (6)Fever; GI symptoms; confusion (5); lymphadenopathy (9); skin rash (30); respiratory symptoms (12); conjunctivitis (26); peripheral edema (9); mucosal changes (17); sore throat (6); shock (29)Dilated coronary arteries (z-score > 2) (8) z-score > 2.5 (7) giant aneurysm (2)LV dysfunction (18/29)4/58: atrial fibrillation (1)1st-degree AV block (1) Second-degree AV block (1) intractable broad complex tachycardia (1)Elevated Elevated 15 cases were positiveIgG+ (40/46)
Dolinger et al. (23)114MCrohn disease-Persistent fever; GI symptoms; rash; hypotension -----Positive-
Feldstein et al. (17)1863 - 12115 M,71 FPreviously healthy (135) 51/186 had an underlying disease other than obesity (autoimmune or immunocompromise (10), respiratory (33), cardiac (5)) BMI-based obesity (45)White (35); Black (46); Latino or Hispanic (57)Persistent fever; GI symptoms (171); conjunctivitis (103); skin rash (110); lymphadenopathy (18); peripheral edema (69); respiratory symptoms (131); oral mucosal changes (78); cardiovascular symptoms (149)Coronary artery aneurysm (z score ≥ 2.5) (15/170)Myocardial dysfunction (90)Arrhythmia (12)Elevated (50/128)Elevated (73/173)73 cases were positiveIgM/IgG+ (85)
Dufort et al. (15)990 - 2053 M, 46 FPre-existing condition (36/99): 29 of them had obesityWhite (29); Black (31); Hispanic (31) Persistent fever or chills, GI symptoms (79); rash (59); swollen hands or feet (9); hypotension (61); mucosal change (60), neurologic symptoms (30); shock (10); lower respiratory symptoms (40); upper respiratory (27); chest pain (11)9 had coronary artery aneurysm (4 z-score > 2.5)Some degree of ventricular dysfunction (51) myocarditis (52)-Elevated (63/89)Elevated (74/82) 50 cases were positive IgG+ (76/77); IgM+ (3/77)
Riphagen et al. (24)84 - 143 F; 5 MPreviously healthy (6); autism (1); alopecia areata and allergic rhinitis (1)Afro-Caribbean (6)Persistent fever; GI symptoms (7); myalgia (1); rash (4); odynophagia (3); conjunctivitis (5); headache (2); hypotension/shock (8)Echobright coronary vessels (8) giant aneurysm (1)Mild to severe LV dysfunction: 4; BiV dysfunction: 1; RV dysfunction: 11/8 in context of refractory shock requiring ECMOElevated Elevated 2-
Waltuch et al. (25)45 - 131 F; 3 MPreviously healthy (2); hypothyroidism (1); asthma (1)-Persistent fever; GI symptoms; rash (2); myalgia (1); cough (2); conjunctivitis (3); fatigue (2); hypotensionSlight ectasia (1); Dilated coronary arteries (1); mildly dilated coronary artery (1)Moderately depressed LV function-Elevated (1)Elevated -IgG+ (4)
Licciardi et al. (26)27, 122 MPreviously healthy, PFAPA syndrome (1)-Persistent fever; rash; GI symptoms; hypotension/shock; Peripheral edema; ConjunctivitisNoVentricular dysfunction (2)-Elevated (2)Elevated (1)NegativeIgM+, IgG+
Borocco et al. (27)165 - 128 M, 8 FPreviously healthy (10); asthma (2); overweight (4)-Persistent fever; GI symptoms (13); mucosal changes (14); rash (13); respiratory symptoms (2); anosmia (1); neurological symptoms (9), shock (11); conjunctivitis (15); lymphadenopathy (6); arthritis (1); pericarditis (4)Coronary dilation (3) median z score 2.6Myocarditis (7); LVEF 35%-Elevate (11)Elevated (11)11 cases were positiveIgG+ (7/8)
Jones et al. (28)16 monthsFNone-Persistent fever; mucosal changes; conjunctivitis; peripheral edema; rash; irritability; respiratory symptomsNoNormal ---Positive-
Balasubramanian et al. (29)18MNone Indian Persistent fever; rash; odynophagia; mild respiratory distress; mucosal changes; conjunctivitis; hypotension; peripheral edemaNo Normal ---Positive-
Labe et al. (12)23, 62 MNone -Rash; conjunctivitis; mucosal changes; persistent fever (1); cervical lymphadenopathy-----One case was positive-
Wolfler et al. (16)52 - 168 months2 M, 3 FNone -Persistent fever; GI symptoms; hypotension/shock (5); conjunctivitis (1); rash (3); respiratory distress (1)No Mild-moderate heart dysfunction (5); LVEF < 50% (3)ST, T waves anomalies, atrial fibrillation (1)ElevatedElevatedPositive-
Kaushik et al. (30)336 - 1320 M, 13 FPreviously healthy (17); overweight (4); asthma (5)Latino or Hispanic (15); Black (13)Persistent fever; GI symptoms (23); conjunctivitis (12); rash (14); neurologic involvement (4); respiratory symptoms (11); hypotension (21); mucosal changes (7)Prominent coronary arteries (6) coronary ectasia (2)LVEF < 50% (21); LVEF < 30% (4)-ElevatedElevated11 cases were positiveIgM/IgG+ (27)
Greene et al. (31)111FNone -Persistent fever; rash; GI symptoms; shock; malaise; leg pain; sore throatNoDecreased LV function-ElevatedElevatedPositive-
Rauf et al. (32)15MNone -Persistent fever; conjunctivitis; GI symptoms; hypotension; peripheral edema; pyuriaNo Moderate LV dysfunction (FE = 35%) LV global hypokinesia-ElevatedElevatedNegative -
Deza Leon et al. (33)16FNone -Fever; conjunctivitis; respiratory distress; rash; cardiogenic shock; peripheral edema; odynophagiaNo Mildly diminished; LVEF at onset; severe dysfunction; requiring ECMOJunctional cardiac rhythmElevated-Positive-
Chiotos et al. (34)65 - 141 M, 5 FNone African-American (2); Caucasian (2)Persistent fever (6); rash (2); conjunctivitis (2); GI symptoms (5); shock (6); peripheral edema (1); mucosal changes (3); respiratory failure (4); irritability (2); headache (1)Echobright coronaries (1); diffuse dilation right coronary artery (z-score 3.15) (1)Mild-Moderate LV dysfunction (4)-Elevated (3/5)Elevated3 cases were positive-
Verdoni et al. (35)103 - 167 M, 3 FNoneCaucasianPersistent fever; Peripheral edema; hypotension; conjunctivitis; rash; GI symptoms (6); meningeal signs (4); mucosal changes (4) Coronary aneurysms (> 4 mm) (2)LVEF < 50% (5)-Elevated (5)ElevatedTwo cases were positiveIgM+ (3); IgG+ (8)
Blondiaux et al. (36)46 - 123 F; 1 MNone-Persistent fever; conjunctivitis; rash; GI symptomsNo Transient systolic dysfunction (4) LVEF < 30% (1)ST depression (1) T waves abnormalities (1)ElevatedElevatedNegativeIgG+ (4); IgM+ (1)
Ramcharan et al. (37)157 - 1111 M, 4 F-African/Afro-Caribbean (6); Asian (6); mixed (2)Persistent fever (15); GI symptoms (13); lethargy (4); myalgia (4)Coronary artery abnormalities (14): 1 aneurysm, 6 ectasia, 7 prominentReduced LV fractional shortening (8) LVEF < 55% (12)Abnormal PR interval (9) abnormal T wavesElevated (15)Elevated (15)Two cases were positiveIgM/IgG/IgA+ (12/12)
Rivera-Figueroa et al. (13)15MNone African-AmericanPersistent fever; rash; GI symptoms; shock; conjunctivitis; peripheral edema; mucosal changes No Normal-Elevated-Positive-
Grimaud et al. (38)203 - 1510 M, 10 F--Fever (20); Abdominal pain (20); rash (10); conjunctivitis (6); mucosal changes (5); lymphadenopathy (2)No Cardiogenic/vasoplegic shock (inclusion criteria) (20)-ElevatedElevated10 cases were positiveIgG+ (15)
Raymond et al. (14)17FNone -Cough; chest pain; orthopnea; tachycardia; pericarditis--Low voltage QRS with electrical alternans T-wave inversion in inferior and lateral leads Sinus tachycardiaNot elevatedElevatedPositive-
Jain et al. (39)13M--Fever; urticarial rashes; diarrhea; facial puffiness conjunctivitis; edema of hands and feet--Normal--Positive-
Heidemann et al. (40)35 - 72 M, 1 F--Fever; conjunctivitis; dry and cracked lips Rash; cervical lymphadenopathy; GI symptoms; Shock Dilation of the proximal left arterial descending coronary artery (Z-score: 2.1) and the mean left coronary artery (Z-score: 2.3) seen in one case. Others were normal.Mildly decreased LV function mild mitral insufficiency (2)Early repolarization in the lateral precordial leads low voltages in the limb leads Sinus tachycardia PR interval prolongationElevated-Positive (1)IgG + (3)
Alnashri et al. (41)116M--Fever; diarrhea; vomiting; generalized abdominal pain; pleuritic chest; fissuring of the lower lip; conjunctivitis; bilateral elbow and knee effusion; hypopigmented macular rash on the chest-Hypokinesia of inferior wall with an ejection fraction of 45%Normal Elevated--IgG +
Torres et al. (42)270 - 1414 M, 13 F--Fever (27); abdominal pain (17); diarrhea (17); vomiting (13); rash (14); conjunctivitis (13); oral mucosal changes (11); Cough (7); peripheral extremity changes (7)Coronary artery abnormalities were in one patientMyocardial dysfunction 4/26---1410
Dolhnikoff et al. (43)111FNone AfricanCardiovascular shock; persistent fever. odynophagia; myalgia abdominal painNoDiffuse LV hypokinesia with decreased LVEF (31%) no segmental wall motion abnormalitiesSinus tachycardiaElevatedPositive --
Schematic representation of clinical signs of MIS-C patients (both CDC and WHO criteria are shown)
Schematic representation of clinical signs of MIS-C patients (both CDC and WHO criteria are shown)

5. COVID-19 Infection

Epidemiological information indicates that SARS-CoV-2 is the possible cause of the syndrome, but the causality is unknown (1). Based on the studies mentioned in Table 2, the positivity percentage of the COVID-19 reverse-transcriptase protein chain reaction (RT-PCR) test varies from 0% to 100%. In most reports, it was positive in less than 50% of cases. On the other hand, the majority of the studies had evidence of positive immunoglobulin G (IgG) antibodies. These data suggest that a post-infectious disease is more likely to be responsible for this condition than an active infection (44).

6. Cardiac Involvement

6.1. Cardiac Dysfunction

In most cases diagnosed with MIS-C, left ventricular systolic dysfunction has been reported (Table 2). In the first report of MIS-C, Riphagen et al. (24) found ventricular dysfunction in six out of eight cases. The majority of available studies in the literature also reported that ventricular dysfunction happens in up to 50% of MIS-C patients (Table 2). Two case series mentioned cardiac dysfunction as an inclusion criterion (20, 38). Belhadjer et al. (20) considered an acute LV failure (LV ejection fraction (LVEF) < 50%), and Grimaud et al. considered cardiogenic/vasogenic shock as an inclusion criterion (38). The incidence rate of cardiogenic shock is much greater in this syndrome than in the Kawasaki disease (60% vs. 7%) (45). Matsubara et al. (46) found severe LV dysfunction in MIS-C patients. They suggested that the subclinical myocarditis might lead to ventricular dysfunction.

The pathophysiology of cardiac dysfunction in patients with this syndrome is not known. The possible causes of acute myocardial dysfunction following a COVID-19 infection in adults include hypoxic injury, myocarditis, ischemic heart injury due to coronary artery disease, stress cardiomyopathy (Takotsubo), acute cor pulmonale, and systemic inflammatory response syndrome (SIRS) (47-50).

6.2. Laboratory Findings

The elevated troponin and B-type natriuretic peptide (BNP)/pro-BNP levels have been reported in many patients with MIS-C. In most studies, the elevated BNP and troponin levels have been assessed as biomarkers to diagnose myocardial injury in the absence of cardiac magnetic resonance imaging (CMRI) or myocardial biopsies (15).

6.3. Coronary Involvement

Most reports have mentioned coronary involvement in 0-40% of cases (Table 2) (16, 21, 24, 26, 41). Mild coronary artery dilation with z-scores of 2 - 2.5 has been reported in most cases. However, large coronary artery aneurysm cases have also been mentioned. Some studies found the late development of coronary artery dilation, which necessitates an ongoing follow-up of MIS-C patients.

6.4. ECG Findings

Some case series reported rhythm abnormalities with variable severity in 4% - 58% of patients (Table 2) (18, 22). The most frequently reported arrhythmic manifestations were QTc prolongation, ST-segment changes, and premature atrial or ventricular beats, which all are non-specific. Whittaker et al. (18) reported first- and second-degree atrioventricular blocks, and two other studies mentioned atrial fibrillation (18, 33). Hemodynamic collapse and the need for extracorporeal membrane oxygenation (ECMO) support due to sustained dysrhythmias have also been reported in these patients (18, 24).

6.5. Management

This syndrome is a newly reported condition, and only a few studies have addressed it so far. Our knowledge about it is, therefore, limited, and the treatment of children with MIS has been based on the experts’ advice and the management of Kawasaki disease. Due to the similarity of the symptoms, the treatment method for adults with COVID-19 and other systemic inflammatory diseases can also be used in pediatrics. Management of these children requires a multidisciplinary care team comprising pediatric specialists in cardiology, infectious disease, critical care, and rheumatology.

Generally, the management is decided based on symptoms and their severity. Due to the potential shortage of drug supplies in a pandemic and considering side effects, pharmacotherapy is not recommended for non-hospitalized children. For children who present with mild symptoms, supportive care, including respiratory support and fluid resuscitation, is, therefore, recommended. However, children with hemodynamic instability and severe illness require PICU admission, mostly for inotropic support, which was reported in 20-100% of the cases (15-18, 20-22, 24-27, 30-35, 37, 38). Some of the PICU-admitted children required a veno-arterial (V-A) support (0% - 28%) (15, 17, 18, 20, 24, 30, 33).

Various treatments have been suggested, but their effectiveness is still questionable. Furthermore, these treatments are based on experts’ opinions with no evidence to affirm them.

6.6. Cardiac Support

As mentioned above, a large proportion of children presenting with hemodynamic instability required acute resuscitation. Therefore, it is necessary to follow the pediatric resuscitation guidelines (51). Children suspicious of ventricular dysfunction and cardiogenic shock should receive smaller fluid blouses (e.g., 10 mg/kg), with an evaluation of the signs of fluid overload before each administration.

6.7. Immunomodulatory Therapy

The advantages of using immunomodulatory therapy in the treatment of Kawasaki disease, as well as other systemic inflammatory disorders, are well established (52, 53). An anti-inflammatory therapy, including intravenous immunoglobulins (IVIGs) and corticosteroids, was used in most patients, and a few cases also received an anti-inflammatory dosage of aspirin (15, 16, 18, 20-22, 24, 26, 31, 32, 34-38). It is critical to remember that the administration of IVIG in patients with cardiac dysfunction must be slower to reduce the risk of fluid overload. The dosage of corticosteroids is based on clinical judgment, but in more severe patients, using a low dosage is recommended.

The assessment of the pattern of cytokine storm in patients with MIS-C showed that an important component of this disorder is macrophage activation, as it is also observed in Kawasaki disease and other autoimmune disorders such as systemic lupus erythematosus (35, 54). Therefore, corticosteroids are another option in the treatment of MIS-C patients, as they can modulate this condition. However, corticosteroids may cause hypertension that can further exacerbate the underlying cardiac problem (45).

Two treatment protocols with corticosteroids have been proposed. The first method involves an intravenous injection of 0.8 mg/kg methylprednisolone, twice a day for 5 - 7 days or until achieving a normal CRP level and then continuing with oral treatment with 2 mg/kg/day for 2 - 3 weeks. The second protocol includes intravenous methylprednisolone 10 - 30 mg/kg/day for three days, followed by oral prednisone/prednisolone 2 mg/kg/day for four days or until achieving a normal CRP level and then tapering the treatment over 2 - 3 weeks. It is important to know that corticosteroids should not be administered in an active infection phase (1).

In some studies, cytokine blockers have been used as a supplemental therapy, for example, interleukin 1 receptor antagonist (e.g., anakinra), interleukin 6 (IL-6) inhibitors (e.g., tocilizumab), and tumor necrosis factor (TNF)-α inhibitors (e.g., infliximab) (16, 18, 20, 22-25, 27, 29-31, 34). These drugs can be prescribed for children who do not respond to routine treatments.

6.8. Antiplatelet Treatment and Anticoagulation

Hypercoagulable state, blood stasis due to immobilization, possible endothelial injury, and ventricular dysfunction are the proposed reasons for the increased risk of thrombotic complications. As a result, anticoagulant therapy should be considered based on coagulation tests and symptoms (55, 56).

6.9. Antiviral Therapy

The benefits of antiviral therapy, such as remdesivir, for children with this syndrome are still unknown (57, 58). The reports suggest that MIS-C is more likely a post-infectious complication in children rather than an active infection. Nonetheless, antiviral drugs could be considered in patients with a positive RT-PCR test, after consulting an infectious disease specialist.

7. Conclusions

In conclusion, children seem to proceed better with the novel coronavirus infection than adults. On the other hand, some children show signs and symptoms of MIS-C, which is a severe complication of the disease. Pediatricians should be aware of this syndrome and differentiate it from other differential diagnoses, including the Kawasaki disease. These children can quickly deteriorate and should closely be observed. The etiology of MIS-C is not yet fully understood, and treatment is mostly based on experts’ opinions. More studies are, therefore, required to define evidence-based management for this new syndrome, and our study played a part in this literature contribution.


  • 1.

    Nakra NA, Blumberg DA, Herrera-Guerra A, Lakshminrusimha S. Multi-System Inflammatory Syndrome in Children (MIS-C) Following SARS-CoV-2 Infection: Review of Clinical Presentation, Hypothetical Pathogenesis, and Proposed Management. Children (Basel). 2020;7(7). [PubMed ID: 32630212]. [PubMed Central ID: PMC7401880].

  • 2.

    Farhat AS, Sayedi SJ, Akhlaghi F, Hamedi A, Ghodsi A. Coronavirus (COVID-19) Infection in Newborns. Int J Pediatr. 2020;8(6):11513-7.

  • 3.

    Ludvigsson JF. Systematic review of COVID-19 in children shows milder cases and a better prognosis than adults. Acta Paediatr. 2020;109(6):1088-95. [PubMed ID: 32202343]. [PubMed Central ID: PMC7228328].

  • 4.

    Dong Y, Mo X, Hu Y, Qi X, Jiang F, Jiang Z, et al. Epidemiology of COVID-19 Among Children in China. Pediatrics. 2020;145(6). [PubMed ID: 32179660].

  • 5.

    Liguoro I, Pilotto C, Bonanni M, Ferrari ME, Pusiol A, Nocerino A, et al. SARS-COV-2 infection in children and newborns: a systematic review. Eur J Pediatr. 2020;179(7):1029-46. [PubMed ID: 32424745]. [PubMed Central ID: PMC7234446].

  • 6.

    Sanna G, Serrau G, Bassareo PP, Neroni P, Fanos V, Marcialis MA. Children's heart and COVID-19: Up-to-date evidence in the form of a systematic review. Eur J Pediatr. 2020;179(7):1079-87. [PubMed ID: 32474800]. [PubMed Central ID: PMC7261213].

  • 7.

    Hennon TR, Penque MD, Abdul-Aziz R, Alibrahim OS, McGreevy MB, Prout AJ, et al. COVID-19 associated Multisystem Inflammatory Syndrome in Children (MIS-C) guidelines; a Western New York approach. Prog Pediatr Cardiol. 2020:101232. [PubMed ID: 32837142]. [PubMed Central ID: PMC7244417].

  • 8.

    Ghodsi A, Azarfar A, Ghahremani S. A Review of Coronavirus Disease (COVID-19) in Children. J Pediatr Nephrol. 2020;8(3).

  • 9.

    Castagnoli R, Votto M, Licari A, Brambilla I, Bruno R, Perlini S, et al. Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection in Children and Adolescents: A Systematic Review. JAMA Pediatr. 2020;174(9):882-9. [PubMed ID: 32320004].

  • 10.

    Ghodsi A, Malek A, Ghahremani S. A Review of Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with COVID-19. Hormozgan Med J. 2020;24(4).

  • 11.

    Wells GA, Shea B, O’Connell DA, Peterson J, Welch V, Losos M, et al. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses. Oxford; 2000.

  • 12.

    Labe P, Ly A, Sin C, Nasser M, Chapelon-Fromont E, Ben Said P, et al. Erythema multiforme and Kawasaki disease associated with COVID-19 infection in children. J Eur Acad Dermatol Venereol. 2020;34(10):e539-41. [PubMed ID: 32455505]. [PubMed Central ID: PMC7283825].

  • 13.

    Rivera-Figueroa EI, Santos R, Simpson S, Garg P. Incomplete Kawasaki Disease in a Child with Covid-19. Indian Pediatr. 2020;57(7):680-1. [PubMed ID: 32393680]. [PubMed Central ID: PMC7387257].

  • 14.

    Raymond TT, Das A, Manzuri S, Ehrett S, Guleserian K, Brenes J. Pediatric COVID-19 and Pericarditis Presenting With Acute Pericardial Tamponade. World J Pediatr Congenit Heart Surg. 2020;11(6):802-4. [PubMed ID: 32909890]. [PubMed Central ID: PMC7484599].

  • 15.

    Dufort EM, Koumans EH, Chow EJ, Rosenthal EM, Muse A, Rowlands J, et al. Multisystem Inflammatory Syndrome in Children in New York State. N Engl J Med. 2020;383(4):347-58. [PubMed ID: 32598830]. [PubMed Central ID: PMC7346766].

  • 16.

    Wolfler A, Mannarino S, Giacomet V, Camporesi A, Zuccotti G. Acute myocardial injury: a novel clinical pattern in children with COVID-19. Lancet Child Adolesc Health. 2020;4(8):e26-7. [PubMed ID: 32497521]. [PubMed Central ID: PMC7263818].

  • 17.

    Feldstein LR, Rose EB, Horwitz SM, Collins JP, Newhams MM, Son MBF, et al. Multisystem Inflammatory Syndrome in U.S. Children and Adolescents. N Engl J Med. 2020;383(4):334-46. [PubMed ID: 32598831]. [PubMed Central ID: PMC7346765].

  • 18.

    Whittaker E, Bamford A, Kenny J, Kaforou M, Jones CE, Shah P, et al. Clinical Characteristics of 58 Children With a Pediatric Inflammatory Multisystem Syndrome Temporally Associated With SARS-CoV-2. JAMA. 2020;324(3):259-69. [PubMed ID: 32511692]. [PubMed Central ID: PMC7281356].

  • 19.

    Shulman ST. Pediatric COVID-associated Multi-system Inflammatory Syndrome (PMIS). J Pediatr Infect Dis Soc. 2020.

  • 20.

    Belhadjer Z, Meot M, Bajolle F, Khraiche D, Legendre A, Abakka S, et al. Acute Heart Failure in Multisystem Inflammatory Syndrome in Children in the Context of Global SARS-CoV-2 Pandemic. Circulation. 2020;142(5):429-36. [PubMed ID: 32418446].

  • 21.

    Toubiana J, Poirault C, Corsia A, Bajolle F, Fourgeaud J, Angoulvant F, et al. Kawasaki-like multisystem inflammatory syndrome in children during the covid-19 pandemic in Paris, France: prospective observational study. BMJ. 2020;369:m2094. [PubMed ID: 32493739]. [PubMed Central ID: PMC7500538].

  • 22.

    Cheung EW, Zachariah P, Gorelik M, Boneparth A, Kernie SG, Orange JS, et al. Multisystem Inflammatory Syndrome Related to COVID-19 in Previously Healthy Children and Adolescents in New York City. JAMA. 2020;324(3):294-6. [PubMed ID: 32511676]. [PubMed Central ID: PMC7281352].

  • 23.

    Dolinger MT, Person H, Smith R, Jarchin L, Pittman N, Dubinsky MC, et al. Pediatric Crohn Disease and Multisystem Inflammatory Syndrome in Children (MIS-C) and COVID-19 Treated With Infliximab. J Pediatr Gastroenterol Nutr. 2020;71(2):153-5. [PubMed ID: 32452979]. [PubMed Central ID: PMC7268863].

  • 24.

    Riphagen S, Gomez X, Gonzalez-Martinez C, Wilkinson N, Theocharis P. Hyperinflammatory shock in children during COVID-19 pandemic. Lancet. 2020;395(10237):1607-8. [PubMed ID: 32386565]. [PubMed Central ID: PMC7204765].

  • 25.

    Waltuch T, Gill P, Zinns LE, Whitney R, Tokarski J, Tsung JW, et al. Features of COVID-19 post-infectious cytokine release syndrome in children presenting to the emergency department. Am J Emerg Med. 2020;38(10):2246 e3-6. [PubMed ID: 32471782]. [PubMed Central ID: PMC7255141].

  • 26.

    Licciardi F, Pruccoli G, Denina M, Parodi E, Taglietto M, Rosati S, et al. SARS-CoV-2-Induced Kawasaki-Like Hyperinflammatory Syndrome: A Novel COVID Phenotype in Children. Pediatrics. 2020;146(2). [PubMed ID: 32439816].

  • 27.

    Borocco C, Pouletty M, Galeotti C, Meinzer U, Faye A, Kone-Paut I, et al. Response to 'Correspondence on 'Paediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 mimicking Kawasaki disease (Kawa-COVID19): a multicentre cohort'' by Mastrolia et al. Ann Rheum Dis. 2020. [PubMed ID: 33023959].

  • 28.

    Jones VG, Mills M, Suarez D, Hogan CA, Yeh D, Segal JB, et al. COVID-19 and Kawasaki Disease: Novel Virus and Novel Case. Hosp Pediatr. 2020;10(6):537-40. [PubMed ID: 32265235].

  • 29.

    Balasubramanian S, Nagendran TM, Ramachandran B, Ramanan AV. Hyper-inflammatory Syndrome in a Child With COVID-19 Treated Successfully With Intravenous Immunoglobulin and Tocilizumab. Indian Pediatr. 2020;57(7):681-3. [PubMed ID: 32393681]. [PubMed Central ID: PMC7387261].

  • 30.

    Kaushik S, Aydin SI, Derespina KR, Bansal PB, Kowalsky S, Trachtman R, et al. Multisystem Inflammatory Syndrome in Children Associated with Severe Acute Respiratory Syndrome Coronavirus 2 Infection (MIS-C): A Multi-institutional Study from New York City. J Pediatr. 2020;224:24-9. [PubMed ID: 32553861]. [PubMed Central ID: PMC7293760].

  • 31.

    Greene AG, Saleh M, Roseman E, Sinert R. Toxic shock-like syndrome and COVID-19: Multisystem inflammatory syndrome in children (MIS-C). Am J Emerg Med. 2020;38(11):2492 e5-6. [PubMed ID: 32532619]. [PubMed Central ID: PMC7274960].

  • 32.

    Rauf A, Vijayan A, John ST, Krishnan R, Latheef A. Multisystem Inflammatory Syndrome with Features of Atypical Kawasaki Disease during COVID-19 Pandemic. Indian J Pediatr. 2020;87(9):745-7. [PubMed ID: 32462354].

  • 33.

    Deza Leon MP, Redzepi A, McGrath E, Abdel-Haq N, Shawaqfeh A, Sethuraman U, et al. COVID-19-Associated Pediatric Multisystem Inflammatory Syndrome. J Pediatric Infect Dis Soc. 2020;9(3):407-8. [PubMed ID: 32441749]. [PubMed Central ID: PMC7313914].

  • 34.

    Chiotos K, Bassiri H, Behrens EM, Blatz AM, Chang J, Diorio C, et al. Multisystem Inflammatory Syndrome in Children During the Coronavirus 2019 Pandemic: A Case Series. J Pediatric Infect Dis Soc. 2020;9(3):393-8. [PubMed ID: 32463092]. [PubMed Central ID: PMC7313950].

  • 35.

    Verdoni L, Mazza A, Gervasoni A, Martelli L, Ruggeri M, Ciuffreda M, et al. An outbreak of severe Kawasaki-like disease at the Italian epicentre of the SARS-CoV-2 epidemic: an observational cohort study. Lancet. 2020;395(10239):1771-8. [PubMed ID: 32410760]. [PubMed Central ID: PMC7220177].

  • 36.

    Blondiaux E, Parisot P, Redheuil A, Tzaroukian L, Levy Y, Sileo C, et al. Cardiac MRI in Children with Multisystem Inflammatory Syndrome Associated with COVID-19. Radiology. 2020;297(3):E283-8. [PubMed ID: 32515676]. [PubMed Central ID: PMC7294821].

  • 37.

    Ramcharan T, Nolan O, Lai CY, Prabhu N, Krishnamurthy R, Richter AG, et al. Paediatric Inflammatory Multisystem Syndrome: Temporally Associated with SARS-CoV-2 (PIMS-TS): Cardiac Features, Management and Short-Term Outcomes at a UK Tertiary Paediatric Hospital. Pediatr Cardiol. 2020;41(7):1391-401. [PubMed ID: 32529358]. [PubMed Central ID: PMC7289638].

  • 38.

    Grimaud M, Starck J, Levy M, Marais C, Chareyre J, Khraiche D, et al. Acute myocarditis and multisystem inflammatory emerging disease following SARS-CoV-2 infection in critically ill children. Ann Intensive Care. 2020;10(1):69. [PubMed ID: 32488505]. [PubMed Central ID: PMC7266128].

  • 39.

    Jain MK, Sahu SK, Behera JR, Patnaik S. Multisystem Inflammatory Syndrome in Children Associated with COVID 19 Treated with Oral Steroid. Indian J Pediatr. 2021;88(1):106. [PubMed ID: 32930973]. [PubMed Central ID: PMC7490472].

  • 40.

    Heidemann SM, Tilford B, Bauerfeld C, Martin A, Garcia RU, Yagiela L, et al. Three Cases of Pediatric Multisystem Inflammatory Syndrome Associated with COVID-19 Due to SARS-CoV-2. Am J Case Rep. 2020;21. e925779. [PubMed ID: 32790652]. [PubMed Central ID: PMC7447294].

  • 41.

    Alnashri H, Aljohani N, Tayeb S, Rabie N, AlBenayan E, Alharthi A, et al. A challenging case of multisystem inflammatory syndrome in children related to coronavirus Disease-19 hospitalized under adult medical service. IDCases. 2020;22. e00957. [PubMed ID: 32953455]. [PubMed Central ID: PMC7489252].

  • 42.

    Torres JP, Izquierdo G, Acuna M, Pavez D, Reyes F, Fritis A, et al. Multisystem inflammatory syndrome in children (MIS-C): Report of the clinical and epidemiological characteristics of cases in Santiago de Chile during the SARS-CoV-2 pandemic. Int J Infect Dis. 2020;100:75-81. [PubMed ID: 32861823]. [PubMed Central ID: PMC7452906].

  • 43.

    Dolhnikoff M, Ferreira Ferranti J, de Almeida Monteiro RA, Duarte-Neto AN, Soares Gomes-Gouvea M, Viu Degaspare N, et al. SARS-CoV-2 in cardiac tissue of a child with COVID-19-related multisystem inflammatory syndrome. Lancet Child Adolesc Health. 2020;4(10):790-4. [PubMed ID: 32828177]. [PubMed Central ID: PMC7440866].

  • 44.

    McCrindle BW, Manlhiot C. SARS-CoV-2-Related Inflammatory Multisystem Syndrome in Children: Different or Shared Etiology and Pathophysiology as Kawasaki Disease? JAMA. 2020;324(3):246-8. [PubMed ID: 32511667].

  • 45.

    Rodriguez-Gonzalez M, Castellano-Martinez A, Cascales-Poyatos HM, Perez-Reviriego AA. Cardiovascular impact of COVID-19 with a focus on children: A systematic review. World J Clin Cases. 2020;8(21):5250-83. [PubMed ID: 33269260]. [PubMed Central ID: PMC7674714].

  • 46.

    Matsubara D, Kauffman HL, Wang Y, Calderon-Anyosa R, Nadaraj S, Elias MD, et al. Echocardiographic Findings in Pediatric Multisystem Inflammatory Syndrome Associated With COVID-19 in the United States. J Am Coll Cardiol. 2020;76(17):1947-61. [PubMed ID: 32890666]. [PubMed Central ID: PMC7467656].

  • 47.

    Shi S, Qin M, Shen B, Cai Y, Liu T, Yang F, et al. Association of Cardiac Injury With Mortality in Hospitalized Patients With COVID-19 in Wuhan, China. JAMA Cardiol. 2020;5(7):802-10. [PubMed ID: 32211816]. [PubMed Central ID: PMC7097841].

  • 48.

    Creel-Bulos C, Hockstein M, Amin N, Melhem S, Truong A, Sharifpour M. Acute Cor Pulmonale in Critically Ill Patients with Covid-19. N Engl J Med. 2020;382(21). e70. [PubMed ID: 32374956]. [PubMed Central ID: PMC7281714].

  • 49.

    Zheng YY, Ma YT, Zhang JY, Xie X. COVID-19 and the cardiovascular system. Nat Rev Cardiol. 2020;17(5):259-60. [PubMed ID: 32139904]. [PubMed Central ID: PMC7095524].

  • 50.

    Tersalvi G, Vicenzi M, Calabretta D, Biasco L, Pedrazzini G, Winterton D. Elevated Troponin in Patients With Coronavirus Disease 2019: Possible Mechanisms. J Card Fail. 2020;26(6):470-5. [PubMed ID: 32315733]. [PubMed Central ID: PMC7166030].

  • 51.

    Edelson DP, Sasson C, Chan PS, Atkins DL, Aziz K, Becker LB, et al. Interim Guidance for Basic and Advanced Life Support in Adults, Children, and Neonates With Suspected or Confirmed COVID-19: From the Emergency Cardiovascular Care Committee and Get With The Guidelines-Resuscitation Adult and Pediatric Task Forces of the American Heart Association. Circulation. 2020;141(25):e933-43. [PubMed ID: 32270695]. [PubMed Central ID: PMC7302067].

  • 52.

    Pineton de Chambrun M, Luyt CE, Beloncle F, Gousseff M, Mauhin W, Argaud L, et al. The Clinical Picture of Severe Systemic Capillary-Leak Syndrome Episodes Requiring ICU Admission. Crit Care Med. 2017;45(7):1216-23. [PubMed ID: 28622216].

  • 53.

    Thompson PD, Myerburg RJ, Levine BD, Udelson JE, Kovacs RJ. Eligibility and disqualification recommendations for competitive athletes with cardiovascular abnormalities: task force 8: coronary artery disease: a scientific statement from the American Heart Association and American College of Cardiology. Circulation. 2015;132(22):e310-e4.

  • 54.

    Ravelli A, Minoia F, Davi S, Horne A, Bovis F, Pistorio A, et al. 2016 Classification Criteria for Macrophage Activation Syndrome Complicating Systemic Juvenile Idiopathic Arthritis: A European League Against Rheumatism/American College of Rheumatology/Paediatric Rheumatology International Trials Organisation Collaborative Initiative. Ann Rheum Dis. 2016;75(3):481-9. [PubMed ID: 26865703].

  • 55.

    Wright FL, Vogler TO, Moore EE, Moore HB, Wohlauer MV, Urban S, et al. Fibrinolysis Shutdown Correlation with Thromboembolic Events in Severe COVID-19 Infection. J Am Coll Surg. 2020;231(2):193-203 e1. [PubMed ID: 32422349]. [PubMed Central ID: PMC7227511].

  • 56.

    Raval JS, Burnett AE, Rollins-Raval MA, Griggs JR, Rosenbaum L, Nielsen ND, et al. Viscoelastic testing in COVID-19: a possible screening tool for severe disease? Transfusion. 2020;60(6):1131-2. [PubMed ID: 32374920]. [PubMed Central ID: PMC7267656].

  • 57.

    Beigel JH, Tomashek KM, Dodd LE, Mehta AK, Zingman BS, Kalil AC, et al. Remdesivir for the Treatment of Covid-19 - Final Report. N Engl J Med. 2020;383(19):1813-26. [PubMed ID: 32445440]. [PubMed Central ID: PMC7262788].

  • 58.

    Goldman JD, Lye DCB, Hui DS, Marks KM, Bruno R, Montejano R, et al. Remdesivir for 5 or 10 Days in Patients with Severe Covid-19. N Engl J Med. 2020;383(19):1827-37. [PubMed ID: 32459919]. [PubMed Central ID: PMC7377062].