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Patient handout

Cardiogenic shock — giant cell myocarditis (GCM)

PRODUCTION

1. Your condition

This handout is for cardiogenic shock — giant cell myocarditis (gcm). Your care team identified this based on: previously healthy young-to-middle-aged adult with rapid (days-to-weeks) progression of acute hf to cardiogenic shock — high suspicion for gcm, especially if associated with vt/vf storm or av block.

Other reasons your team may use this plan: sustained vt/vf storm (≥3 episodes in 24 h) in setting of acute myocarditis — gcm until proven otherwise (50-60% of gcm cases per cooper 1997 + kandolin 2013); emergent emb indication; new high-grade av block (mobitz ii / complete heart block) in acute myocarditis — gcm is the leading clue (15-50% per kandolin 2013); emergent emb indication; endomyocardial biopsy showing multinucleated giant cells (cd68+, s-100−) + lymphocyte infiltrate (t-cell predominant) + myocyte necrosis without non-caseating granulomas (differential vs sarcoidosis) — diagnostic gcm.

2. Your medications

Take these medications exactly as prescribed. Do not stop or change a dose without talking to your provider.

MedicationStarting doseHowWhenWhat it does
norepinephrine0.05–0.5 µg/kg/min titrate MAP ≥65IVcontinuousSOAP-II PMID 20200382 — NE first-line in CS
dobutamine2.5 µg/kg/min CAUTIOUS titration; AVOID in ventricular electrical stormIVcontinuousDOREMI PMID 33704937; CAUTION in GCM given high VT/VF risk; escalate to MCS over higher inotrope doses
methylprednisolone1000 mg IV daily × 3-5 days then prednisone 1 mg/kg/d taper over monthsIVdailyCooper Multicenter GCM Registry NEJM 1997 (PMID 9197214) + GIANT-2 protocol (PMID 18369191) — cornerstone of combined immunosuppression
cyclosporine3-5 mg/kg/d divided BID; trough target 200-300 ng/mL acute then 100-200 ng/mL maintenancePO/IVBIDCooper NEJM 1997 + GIANT-2 — combination cyclosporine + steroids markedly improves transplant-free survival from ~10% to ~70%; ESC 2013 myocarditis position paper
basiliximab20 mg IV day 0 + day 4 (induction)IVq4d × 2 dosesGIANT-2 protocol PMID 18369191 — IL-2RA induction in GCM; transplant immunology precedent (basiliximab is standard induction in solid organ transplant)
rabbit anti-thymocyte globulin1.5 mg/kg/d IV × 5-14 days (induction); replaces historical OKT3 (muromonab) which is no longer availableIVdaily × 5-14 dCooper GIANT-2 protocol PMID 18369191 — anti-T-cell induction in GCM; historically OKT3 (muromonab) used but no longer manufactured; ATG is contemporary equivalent
azathioprine1-2 mg/kg/d PO daily (chronic maintenance)POdailyGIANT-2 protocol PMID 18369191 — chronic maintenance after acute phase; purine antimetabolite
mycophenolate mofetil1000 mg PO BID (chronic maintenance alternative to AZA)POBIDSolid organ transplant precedent + GIANT-2 — alternative to AZA
amiodarone150 mg IV bolus then 1 mg/min × 6 h then 0.5 mg/minIVcontinuousAHA 2020 ACLS Class IIb for refractory VT/VF; high baseline arrhythmia risk in GCM (50-60%); consider catheter ablation if refractory
lidocaine1-1.5 mg/kg IV bolus then 1-4 mg/min infusionIVcontinuousAHA 2020 ACLS alternative for refractory VT/VF
magnesium sulfate2 g IV bolus over 5-15 min then maintenance to keep Mg ≥2.0IVas neededAHA 2020 ACLS for torsades; standard electrolyte repletion
sulfamethoxazole-trimethoprim1 SS tab PO daily or 1 DS tab PO MWFPOdaily/MWFPJP prophylaxis on chronic high-dose steroid + cyclosporine; standard transplant immunology
valganciclovir900 mg PO daily × 3-6 mo per CMV serostatusPOdailyCMV prophylaxis on ATG / IL-2RA / chronic immunosuppression; standard transplant immunology

Plan: Giant cell myocarditis CS — combined immunosuppression per Cooper GIANT-2 protocol (methylprednisolone + cyclosporine + IL-2RA + ATG induction; chronic maintenance with cyclosporine + low-dose steroids + AZA/MMF) + early MCS bridge + transplant listing priority

3. When to call your provider

Contact your care team if any of the following happen:

  • Sustained VT / syncope / ICD shock → EP urgent consult; transplant escalation
  • Persistent severe LV dysfunction → expedite transplant
  • Recurrent GCM on surveillance EMB → escalate immunosuppression OR expedite transplant
  • Opportunistic infection → ID urgent consult
  • Post-transplant graft GCM recurrence → re-escalate immunosuppression; consider re-transplant in selected cases
  • Skin cancer / PTLD → oncology + transplant team

4. When to seek emergency care

Call 911 or go to the nearest emergency room right away if you have:

  • Recurrent VT/VF storm in GCM (50-60% of cases per Cooper 1997 + Kandolin 2013) — amiodarone + EP consult + ICD implantation given high recurrent arrhythmia risk; refractory cases → catheter ablation; transplant escalation(life-threatening)
  • New high-grade AV block (Mobitz II / complete heart block) in GCM (15-50% of cases per Kandolin 2013) — transvenous pacemaker → permanent pacemaker (often biventricular if HFrEF); AV block is the major diagnostic clue distinguishing GCM from viral myocarditis
  • GCM with refractory CS on optimal therapy OR refractory VT/VF on optimal therapy OR MCS-dependent — UNOS 1A transplant listing priority; high recurrence in graft (20-25%) but transplant remains best option given dismal medical mortality(life-threatening)
  • GCM recurrence in transplanted graft on surveillance EMB (20-25% per Kandolin 2013 + Ekström 2024) — re-escalate immunosuppression intensity (steroid pulse + cyclosporine trough increase + add MMF if not already + consider abatacept/ATG re-induction); selected patients may require re-transplant
  • Refractory CS in GCM despite cautious vasopressor / inotrope — escalate to MCS (IABP / Impella / VA-ECMO) early; bridge to combined immunosuppression response, recovery, or transplant; recovery possible with combined immunosuppression in 40-50% per Cooper GIANT-2(life-threatening)

5. Follow-up

Repeat echo + CMR at 4-8 wks; continued combined immunosuppression LIFE-LONG OR until transplant; transplant evaluation completion if not yet listed; cardiac rehab; EP follow-up for ICD eligibility per AHA 2017 VA/SCD guideline (high arrhythmic recurrence — most GCM patients receive ICD after acute phase); post-transplant immunosuppression maintained with surveillance for graft GCM recurrence (20-25% per Kandolin 2013 + Ekström 2024)

6. Sources

Guideline: Cooper Multicenter Giant Cell Myocarditis Registry NEJM 1997 (PMID 9197214); Cooper GIANT-2 trial protocol (PMID 18369191); Caforio ESC 2013 myocarditis position paper (PMID 23824828); Tschöpe AHA 2020 myocarditis scientific statement (PMID 32200645); Cooper AHA/ACC/ESC 2007 EMB consensus (PMID 17998456); Birnie HRS 2014 cardiac sarcoidosis (PMID 24682272) — differential

  1. pubmed.ncbi.nlm.nih.gov/9197214
  2. pubmed.ncbi.nlm.nih.gov/18369191
  3. pubmed.ncbi.nlm.nih.gov/17998456