ESC 2025 Guidelines for the Management of Myocarditis and Pericarditis

Comprehensive Summary: Imaging Recommendations with Focus on CMR

Citation: Schulz-Menger J, Imazio M, et al. European Heart Journal 2025;46:3952-4041

Significance: This is the first dedicated ESC guideline for myocarditis and pericarditis, representing a major advancement in standardizing diagnosis and management.

1. Paradigm Change in Myocarditis Diagnosis

The guidelines introduce a fundamental shift: CMR can now provide a “definitive clinical diagnosis” of myocarditis, elevating its role from supportive to diagnostic. This parallels (rather than replaces) endomyocardial biopsy (EMB).

Diagnostic Framework: - CMR-proven myocarditis: Clinical presentation + 2/2 updated Lake Louise Criteria fulfilled - CMR-uncertain: Clinical presentation + only 1/2 Lake Louise Criteria - CMR-rejected: Negative CMR findings

2. CMR Recommendations (Recommendation Table 3)

For Myocarditis

Recommendation Class Level
CMR recommended in suspected myocarditis for diagnosis, including assessment of oedema, ischaemia, and necrosis/fibrosis/scarring I B
CMR recommended for follow-up within 6 months to identify healed vs ongoing process, for risk stratification, personalised therapy, and return to exercise I B

For Pericarditis

Recommendation Class Level
CMR recommended when diagnosis cannot be made using clinical criteria, to assess pericardial thickening, oedema, LGE, and persistence of disease I B

3. Updated Lake Louise Criteria (2018)

The guidelines adopt the updated Lake Louise Criteria as established by Ferreira et al.¹

CMR diagnosis requires at least 1 T2-based criterion + at least 1 T1-based criterion:

T2-based criteria (oedema marker): - Global or regional increase in myocardial T2 relaxation time - Increased signal intensity on T2-weighted imaging

T1-based criteria (injury/fibrosis marker): - Increased myocardial T1 (native) - Increased extracellular volume (ECV) - Late gadolinium enhancement (LGE) in non-ischaemic pattern

Pattern recognition: - LGE typically mid-wall or subepicardial (not following coronary distribution) - Lateral and inferior walls most commonly affected - Certain patterns suggest specific aetiologies (e.g., ring-like septal LGE in desmoplakin cardiomyopathy)

4. Technical Considerations

Timing: CMR has highest diagnostic accuracy when performed within the first 2 weeks of symptom onset.

Tissue characterisation targets: 1. Myocardial oedema (T2 mapping, T2-weighted imaging) 2. Hyperaemia and capillary leak (T1 mapping, ECV) 3. Necrosis/fibrosis (LGE)

Limitations addressed: - Ferromagnetic implants cause artefacts but dedicated techniques now available - CMR feasible in intubated patients with fast/motion-corrected imaging - Non-conditional devices: CMR possible with clear clinical indication if other modalities unhelpful

Important caveat: CMR evidence of inflammation does NOT provide the underlying histotype (viral vs immune-mediated vs other)—EMB still needed for this in selected cases.

5. Risk Stratification by Imaging Findings

High-Risk Features (imaging criteria):

  • Extensive LGE (≥2 segments)
  • Reduced LVEF
  • Pericardial effusion with tamponade features
  • Extensive pericardial LGE on CMR

Low-Risk Features:

  • Minimal or no LGE (<2 segments)
  • Normal LVEF
  • No pericardial effusion or small stable effusion
  • Resolution of oedema on follow-up CMR

6. Other Imaging Modalities

Echocardiography

  • First-line imaging in all suspected cases (Class I)
  • Strain imaging (speckle tracking/TDI) can detect subclinical dysfunction
  • Monitors: chamber size, ventricular function, wall thickness, pericardial effusion
  • Less specific than CMR but widely available

CT (Recommendation Table 4)

  • Class I for evaluating pericardial thickness, calcifications, masses, loculated effusions
  • Important pre-pericardiectomy for calcification burden assessment

Nuclear Medicine (Recommendation Table 5)

  • FDG-PET/CT: Class IIa when echo and CMR inconclusive
  • Requires carbohydrate-free preparation protocol
  • Particularly useful for cardiac sarcoidosis and extracardiac involvement
  • Alternative when CMR unsuitable (irregular rhythm, device artefacts)

7. Follow-up Imaging Protocol

The guidelines emphasise that follow-up CMR within 6 months is Class I recommended to: - Distinguish healed myocarditis from ongoing/chronic inflammation - Inform decisions on return to exercise (especially athletes) - Guide therapy duration - Provide prognostic information

Evidence supporting serial CMR comes from multiple studies demonstrating that CMR detects persistent disease activity even when biomarkers have normalised.² The prognostic value of repeat CMR has been established in studies showing that patients with persistent LGE + oedema have significantly worse outcomes (86% cardiac event rate over 7 years) compared to those with complete resolution (0% events).³

Key prognostic indicators on follow-up: - Persistent oedema = ongoing inflammation - New or increasing LGE = progression - Resolution of oedema with stable/decreasing LGE = healing

8. Clinical Algorithms Integration

CMR is positioned as a key decision node in all diagnostic pathways: - Chest pain presentation: CMR to differentiate myocarditis from ACS - Heart failure presentation: CMR for tissue characterisation - Arrhythmia presentation: CMR to detect inflammatory substrate - Pericarditis with diagnostic uncertainty: CMR for tissue diagnosis

9. Summary: What Clinicians Should Do

  1. Order CMR early (within 2 weeks) in suspected myocarditis
  2. Use multiparametric protocol: T1 mapping, T2 mapping, ECV, LGE
  3. Apply updated Lake Louise Criteria for interpretation
  4. Plan follow-up CMR at ~6 months for risk stratification
  5. Consider FDG-PET if CMR inconclusive or contraindicated
  6. Reserve EMB for high-risk patients or when histotype knowledge changes management

Key CMR References

  1. Ferreira VM, Schulz-Menger J, Holmvang G, et al. Cardiovascular magnetic resonance in nonischemic myocardial inflammation: expert recommendations. J Am Coll Cardiol 2018;72:3158-76. [Updated Lake Louise Criteria]

  2. Berg J, Kottwitz J, Baltensperger N, et al. Cardiac magnetic resonance imaging in myocarditis reveals persistent disease activity despite normalization of cardiac enzymes and inflammatory parameters at 3-month follow-up. Circ Heart Fail 2017;10:e004262.

  3. Aquaro GD, Ghebru Habtemicael Y, Camastra G, et al. Prognostic value of repeating cardiac magnetic resonance in patients with acute myocarditis. J Am Coll Cardiol 2019;74:2439-48. [Key prognostic serial CMR study; n=202]

  4. Lurz P, Luecke C, Eitel I, et al. Comprehensive cardiac magnetic resonance imaging in patients with suspected myocarditis: the MyoRacer-Trial. J Am Coll Cardiol 2016;67:1800-11. [Multiparametric CMR diagnostic accuracy]

Document prepared for www.cardiac-imaging.org Last updated: January 2026