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COVID-19 / MIS-C

Learning Objectives

Core Knowledge & Clinical Reasoning

  • [ ] Apply MIS-C diagnostic criteria (CDC case definition) differentiating from Kawasaki and sepsis
  • [ ] Analyze cardiac involvement patterns in MIS-C (cardiomyopathy, coronary aneurysms, arrhythmias)
  • [ ] Evaluate severity of cardiac involvement to guide treatment intensification
  • [ ] Determine appropriate follow-up schedule based on severity (2 weeks to 6 months restriction)

Management Decisions

  • [ ] Formulate initial treatment regimen (IVIG + steroids; escalation to anakinra for refractory cases)
  • [ ] Develop individualized return-to-play protocol based on cardiac findings

Communication & Counseling

  • [ ] Counsel families on expected cardiac recovery timeline (typically good prognosis)
  • [ ] Explain exercise restriction rationale and clearance requirements
  • [ ] Address family concerns about long-term COVID cardiovascular effects

Systems-Based Practice

  • [ ] Coordinate multidisciplinary care (cardiology, rheumatology, ICU)
  • [ ] Ensure appropriate cardiology follow-up scheduling per ACR recommendations

Key Guidelines

2022 AHA Scientific Statement: SARS-CoV-2 and Cardiovascular Manifestations in Children Circulation. 2022

MIS-C Epidemiology

  • Incidence: ~1 per 3,000 SARS-CoV-2 infections
  • Median age: 8 years
  • Typically 2-6 weeks after acute infection
  • Decreased incidence with vaccination

Cardiac Involvement in MIS-C

Manifestation Prevalence
Cardiomyopathy 28-55%
Coronary aneurysms 12-21%
Myocarditis 18%
Pericardial effusion 23%
Arrhythmias Variable

Diagnostic Criteria (CDC Case Definition)

All criteria must be met: 1. Age <21 years 2. Fever ≥38°C for ≥24 hours OR subjective fever ≥24 hours 3. Laboratory evidence of inflammation (elevated CRP, ESR, fibrinogen, procalcitonin, D-dimer, ferritin, LDH, IL-6, neutrophils, or low lymphocytes/albumin) 4. Severe illness requiring hospitalization 5. Multisystem involvement (≥2 organs: cardiac, renal, respiratory, hematologic, GI, dermatologic, neurologic) 6. Evidence of SARS-CoV-2 (PCR, serology, antigen, or exposure within 4 weeks) 7. No alternative plausible diagnosis

Initial Cardiac Evaluation

  • ECG: ST changes, low voltages, arrhythmias
  • Troponin: Elevated in myocarditis/injury
  • BNP/NT-proBNP: LV dysfunction marker
  • Echocardiography:
  • LV function (often depressed)
  • Coronary arteries (aneurysms)
  • Pericardial effusion
  • Valvular regurgitation

Treatment

Anti-inflammatory Therapy

  • IVIG: 2 g/kg (similar to Kawasaki)
  • Corticosteroids: Methylprednisolone 1-2 mg/kg/day
  • Anakinra: For refractory cases

Supportive Care

  • ICU monitoring if hemodynamically unstable
  • Inotropic support (milrinone) for cardiogenic shock
  • Anticoagulation/antiplatelet therapy individualized

Follow-up Recommendations (ACR)

Timepoint Evaluation
7-14 days Echo, ECG
4-6 weeks Echo, ECG, consider Holter
3-6 months Echo, exercise testing if active
Long-term Annual if any residual abnormality

Exercise Restriction

Cardiac Involvement Restriction Duration
None 2 weeks minimum
Mild (EF 45-55%, minor changes) 3 months
Moderate-Severe 6 months minimum

Return-to-play requires: - Normal echo - Normal Holter (if arrhythmias present) - Normal exercise stress test - Cardiology clearance

Post-COVID Cardiovascular Sequelae (2025 RECOVER Data)

Children post-COVID infection have increased risk of: - Hypertension - Ventricular arrhythmias - Myocarditis - Heart failure - Cardiomyopathy

Board Pearls

Pearl: MIS-C echo follow-up: 7-14 days and 4-6 weeks minimum

Even if initial echo normal, repeat imaging required

Pearl: Exercise restriction: 2 weeks (no involvement) to 6 months (significant)

Requires normal echo, Holter, and stress test before return

Self-Assessment

Q1: An 8-year-old presents with fever for 4 days, abdominal pain, rash, and hypotension. Labs show elevated CRP, troponin, and BNP. PCR for SARS-CoV-2 is positive. Echo shows EF of 40%. What is the most likely diagnosis and initial treatment?

Answer **Answer**: MIS-C; IVIG + corticosteroids **Rationale**: This patient meets MIS-C criteria: fever, multisystem involvement (GI, dermatologic, cardiac), laboratory inflammation, severe illness, and COVID evidence. Treatment includes IVIG (2 g/kg) and corticosteroids. Inotropic support may be needed for cardiogenic shock.

References

  • AHA Scientific Statement. Circulation. 2022
  • CDC MIS-C Case Definition
  • ACR Follow-up Recommendations