What is the recommended workup and treatment for cardiac sarcoidosis?

Cardiac Sarcoidosis: Diagnostic Workup and Treatment

Cardiac MRI or PET-CT with fluorodeoxyglucose imaging should be the primary diagnostic test for suspected cardiac sarcoidosis, followed by corticosteroid therapy as the mainstay of treatment. 1

Diagnostic Workup

Initial Evaluation

• Echocardiography is essential for all patients with suspected cardiac sarcoidosis to assess ventricular function and wall motion abnormalities 1
• 24-hour Holter monitoring to detect arrhythmias (>100 ventricular ectopic beats in 24 hours is considered significant) 1
• ECG to identify conduction abnormalities (recommended as baseline screening even in asymptomatic patients with extracardiac sarcoidosis) 1

Advanced Imaging

1. Cardiac MRI with late gadolinium enhancement:

   • First-line imaging study of choice for suspected cardiac sarcoidosis 1
   • Identifies both active inflammation (early enhancement in T2-weighted images) and fibrosis/scarring (late enhancement) 1
   • Characteristic distribution: mid-myocardial with preferential involvement of basal septum and lateral walls 1

2. PET-CT with fluorodeoxyglucose:

   • Alternative when cardiac MRI is unavailable 1
   • Higher diagnostic accuracy than older techniques 1
   • Can predict adverse clinical events and monitor treatment response 1
   • Particularly useful for detecting active inflammation 2

3. Endomyocardial Biopsy (EMB):

   • Limited sensitivity (25-50% of autopsy-confirmed cases) due to patchy nature of cardiac involvement 1
   • Useful when positive (showing noncaseating granulomas) but negative results do not rule out cardiac sarcoidosis 1
   • Consider when diagnosis remains uncertain after non-invasive testing 1

Treatment Approach

Immunosuppressive Therapy

1. Corticosteroids:

   • Mainstay of therapy for cardiac sarcoidosis 1
   • Typically initiated at high dose (prednisone 40-60 mg daily) 1
   • Tapered slowly over months if clinical/imaging features remain stable or improve 1
   • Close follow-up for relapse after discontinuation 1

2. Alternative Immunosuppressants (for steroid-intolerant patients or those with inadequate response):

   • Methotrexate, azathioprine, mycophenolate mofetil 1
   • Cyclophosphamide, pentoxifylline, thalidomide 1
   • Consider in collaboration with pulmonologist or rheumatologist 1

Management of Cardiac Complications

1. Heart Failure Management:

   • Standard guideline-directed medical therapy for heart failure with reduced ejection fraction 1

2. Arrhythmia Management:

   • ICD implantation recommended for:
     • Patients with sustained ventricular tachycardia or survivors of cardiac arrest 1
     • LVEF ≤35% 1
     • Patients with LVEF >35% who have syncope and/or evidence of myocardial scar on cardiac MRI or PET 1
     • Patients with an indication for permanent pacing 1

3. Advanced Heart Failure:

   • Cardiac transplantation for end-stage heart failure or intractable arrhythmias 1
   • Better short and intermediate-term survival compared to transplantation for other causes 1

Prognostic Factors

• Important predictors of mortality include:
  • LV end-diastolic diameter
  • NYHA functional class
  • Sustained ventricular tachycardia 1
• Survival reported at 89% for patients with EF ≥50% 1
• Recent data indicates 90-96% 5-year survival with appropriate management 3

Common Pitfalls and Caveats

• Isolated cardiac sarcoidosis (without extracardiac involvement) is particularly challenging to diagnose 4
• Cardiac sarcoidosis can be the first or only manifestation of sarcoidosis 3
• Negative endomyocardial biopsy does not exclude the diagnosis due to sampling error 1, 5
• Septal involvement on imaging is a characteristic finding that should raise suspicion 5
• Treatment of asymptomatic or minimally symptomatic patients remains controversial 1
• Sarcoidosis can recur in transplanted hearts but typically responds to steroid therapy 1

By following this systematic approach to diagnosis and treatment, mortality and morbidity from cardiac sarcoidosis can be significantly reduced, with recent data showing substantial improvements in long-term survival with appropriate management.