Multichamber Strain Recovery in Acute Myocarditis: Evidence From the MyocarditIRM Study

Presenting Author(s)

• 

  Paul Garrigoux

  Medical Student
  Sorbonne Université, Department of Cardiovascular Imaging, Sorbonne Université, Pitié-Salpêtrière University Hospital AP-HP, INSERM 1146, CNRS 7371, Laboratoire d'Imagerie Biomédicale, Paris, France, France

Primary Author(s)

• 

  Paul Garrigoux

  Medical Student
  Sorbonne Université, Department of Cardiovascular Imaging, Sorbonne Université, Pitié-Salpêtrière University Hospital AP-HP, INSERM 1146, CNRS 7371, Laboratoire d'Imagerie Biomédicale, Paris, France, France

Co-Author(s)

• AT

  Anne Tavian

  Medical student
  Sorbonne Université, Department of Cardiovascular Imaging, Sorbonne Université, Pitié-Salpêtrière University Hospital AP-HP,  INSERM 1146, CNRS 7371, Laboratoire d'Imagerie Biomédicale, Paris, France, France
• KB

  Khaoula Bouazizi, PhD

  Rsearch engineer
  Laboratoire d'Imagerie Biomédicale
  Paris, Ile-de-France, France
• MZ

  Mohamed Zarai, MSc

  Research Engineer
  Sorbonne Université, Department of Cardiovascular Imaging, Sorbonne Université, Pitié-Salpêtrière University Hospital AP-HP,  Paris, France, France
• SB

  Samia Boussouar, MD, MSc

  MD
  Assistance Publique – Hôpitaux de Paris
  Paris, Ile-de-France, France
• 

  Alexis Jacquier, MD, PhD

  Prof
  Aix Marseille Univ, CNRS, CRMBM, Marseille, France; APHM, Hôpital Universitaire Timone, Radiology Dept, Marseille, France
  Marseille, Provence-Alpes-Cote d'Azur, France
• LN

  Lan-anh Nguyen, MD

  MD
  Assistance Publique – Hôpitaux de Paris, France
• TW

  Tatiana Wong, MD

  Attending physician
  Sorbonne Université, Department of Cardiovascular Imaging, Sorbonne Université, Pitié-Salpêtrière University Hospital AP-HP,  INSERM 1146, CNRS 7371, Laboratoire d'Imagerie Biomédicale, Paris, France, France
• CC

  Cécile Chung

  Attending physician
  Sorbonne Université, Department of Cardiovascular Imaging, Sorbonne Université, Pitié-Salpêtrière University Hospital AP-HP,  INSERM 1146, CNRS 7371, Laboratoire d'Imagerie Biomédicale, Paris, France, France
• NP

  Nicoletta Pasi, MD

  MD
  Assistance Publique – Hôpitaux de Paris
  Paris, Ile-de-France, France
• TG

  Thibaud Genet, MD

  Attending physician
  Cardiology Department, University Hospital of Tours, Tours, France, France
• Ol

  Olivier lairez

  Attending physician
  Department of Cardiology, University Hospital of Rangueil, Toulouse, France., France
• JD

  Jean-François Deux, MD, PhD

  Radiologist
  Geneva University Hospitals, Switzerland
• BA

  Benjamin Alos, MD

  Attending physician
  University of Poitiers, Clinical Investigation Center (Inserm 1402), University Hospital of Poitiers, Cardiology Department, Poitiers, FACT network, France, France
• EM

  Elie Mousseaux, MD, PhD

  Professor
  Université Paris Cité, INSERM, PARCC, APHP, Hôpital Européen Georges Pompidou, France
• PO

  Phalla Ou, MD, PhD

  Professor in radiology
  Radiology Department, Bichat University Hospital, Assistance Publique–Hôpitaux de Paris, Paris, France, France
• 

  Nadjia Kachenoura, PhD

  PhD
  Laboratoire d'Imagerie Biomédicale, Sorbonne Université
  Paris, Ile-de-France, France
• CB

  Claire Bouleti

  Professor in cardiology
  University of Poitiers, Clinical Investigation Center (Inserm 1402), University Hospital of Poitiers, Cardiology Department, Poitiers, FACT network, France, France
• 

  Alban Redheuil, MD PhD

  MD, PhD
  Assistance Publique – Hôpitaux de Paris, France

Background: CMR has become the first-line imaging modality for the diagnosis and monitoring of acute myocarditis (AM), due to its ability to noninvasively characterize myocardial tissue¹. Myocardial strain may be a sensitive marker of subclinical myocardial dysfunction in acute myocarditis, potentially providing incremental diagnostic and prognostic value beyond ejection fraction and LGE^2-4. Multilayer strain may have further diagnostic value as epicardial and midmyocardial layers are primarily involved in myocarditis⁵ which remains associated with heart failure and ventricular arrhythmias despite often favorable short-term outcomes.

However, large scale longitudinal multichamber strain data remains lacking. Our aim was to describe the distribution of conventional and multilayer strain parameters in acute myocarditis and their evolution during follow-up.

Methods: Among 803 consecutive patients with AM enrolled in the MyocarditIRM study⁶ (French National Multicenter Prospective Observational Study of CMR-confirmed AM), all who underwent follow-up CMR (FU) (N=288) with appropriate image quality (N=264) were included. All CMR exams were analyzed centrally by a certified CoreLab blinded to clinical data. Multichamber (LV, RV, LA) 3D strain analysis was performed using feature-tracking (FT) (QStrain, MEDIS) on cine-SSFP images. LV endocardium and epicardium were contoured on short-axis and 2-, 3-, and 4-chamber long-axis views to obtain multilayer strains. RV free wall and LA reservoir peak endocardial strains were assessed on long-axis views. Strain curves were averaged to report longitudinal changes (Figure). Changes in peak strains were compared using the paired Wilcoxon rank test.

Results: Of 264 patients, 82% were men, mean age 33 ± 12 years, with a median follow-up of 163 days [IQR 92–201]. LV, RV, and LA ejection fractions increased by ~3 points at follow-up. LV global longitudinal strain improved from –21.1% ± 3.57 to –22.4% ± 3.27, and circumferential strain from –21.8% ± 4.25 to –23.1% ± 3.36 (both P< 0.001). Improvements were consistent across all myocardial layers and also significant for LV radial strain and inward displacement. RV free-wall longitudinal strain improved from –30.8% ± 6.91 to –32.2% ± 7.03, while LA strain increased from 40.8% ± 14.8 to 44.9% ± 13.4. Despite the predominant lateral epicardial pattern of late gadolinium enhancement and edema, findings indicate global cardiac involvement in acute myocarditis. Overall, follow-up showed progressive recovery of biventricular and atrial strain.

Conclusion: Conventional biventricular and LA strain parameters, along with multilayer LV strain, improved significantly during follow-up of acute myocarditis. Comprehensive FT-strain CMR may refine individual diagnosis and prognosis. Future studies should explore associations with clinical, tissue characterization, and outcome data.

Comparison of multichamber peak strain values and ejection fractions by FT-CMR from acute myocarditis to a median 6-month follow-up (Nf264).
Note: FT-CMR = feature-tracking cardiac magnetic resonance; LV = left ventricle; RV = right ventricle; LA = left atrium; GLS = global longitudinal strain; GCS = global circumferential strain; GRS = global radial strain. Endo = endocardium, Myo = mid-myocardium, Epi = epicardium. Blue curves represent baseline (acute phase), red curves represent follow-up (~6 months).
Note: FT-CMR = feature-tracking cardiac magnetic resonance; LVEF = left ventricular ejection fraction; RVEF = right ventricular ejection fraction; LAEF = left atrial ejection fraction; GLS = global longitudinal strain; GCS = global circumferential strain; GRS = global radial strain.