Arrhythmic Risk in Myocarditis Outcome Research (ARMOR)

Incidence, Clinical Impact, and Prediction of Ventricular Arrhythmia in Patients With Acute Myocarditis

The goal of this observational, retrospective, multicenter study is to characterize the arrhythmic burden and identify predictive factors for ventricular arrhythmias (VAs) in adult patients hospitalized for acute myocarditis (AM). The main questions it aims to answer are:

• What is the incidence of sustained ventricular arrhythmias during the index hospitalization in patients with acute myocarditis?
• What clinical, biological, electrocardiographic, and imaging factors predict the occurrence of sustained ventricular arrhythmias during hospitalization and after discharge?

Researchers will compare patients who developed sustained VAs during hospitalization to those who did not, in order to identify independent predictors of arrhythmic events and develop a validated risk stratification score.

Participants' medical records from 2020 to 2024 will be reviewed to collect:

• Baseline demographic, clinical, biological, electrocardiographic, and imaging data at admission
• In-hospital management strategies and outcomes, including mortality, cardiogenic shock, and heart replacement therapy
• Long-term follow-up data including VA recurrence, sudden cardiac death, and development of cardiomyopathy, with censoring applied on January 1, 2026

Study Overview

• Status: Not yet recruiting
• Conditions: Myocarditis Acute; Ventricular Arrhythmia
• Intervention / Treatment: Other: Treatment of acute myocarditis

• Study Type: Observational
• Enrollment (Estimated): 1500

Contacts and Locations

• Study Contact: Name: Miloud M CHERBI, MD; Phone Number: +33761743831; Email: cherbi.m@chu-toulouse.fr
• Study Contact Backup: Name: Clément DELMAS, MD, PhD; Phone Number: +33561322426; Email: delmas.clement@chu-toulouse.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

All adult patients hospitalized for acute myocarditis proven by imaging or histological criteria

Description

Inclusion Criteria:

• Age ≥ 18 years
• Hospitalization for acute myocarditis
• Confirmation of the diagnosis of AM by at least one of the following: (1) Cardiac magnetic resonance according to the revised 2018 Lake Louise Criteria; (2) Endomyocardial biopsy according to the Dallas criteria with associated immunohistochemical and molecular criteria; (3) Cardiac computed tomography with compatible late iodine enhancement

Exclusion Criteria:

• Age < 18 years
• Concomitant acute coronary syndrome

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Acute myocarditis; Patients hospitalized for acute myocarditis confirmed according to current guidelines	Other: Treatment of acute myocarditis; Standard medical and interventional management of acute myocarditis in accordance with local protocols

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ventricular arrhythmia	Number of patients with any sustained ventricular arrhythmia episode (≥ 30 seconds), including ventricular tachycardia and ventricular fibrillation	through study completion, an average of 3 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cardiomyopathy	Number of patients with a new diagnosis of non-ischemic cardiomyopathy	through study completion, an average of 3 years

Collaborators and Investigators

• Sponsor: AZ Sint-Jan AV
• Collaborators: University Hospital, Montpellier; University Hospital, Bordeaux; Poitiers University Hospital; Rennes University Hospital; University Hospital, Toulouse; Institut universitaire de cardiologie et de pneumologie de Québec, University Laval

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): March 31, 2027

Study Registration Dates

• First Submitted: March 23, 2026
• First Submitted That Met QC Criteria: March 26, 2026
• First Posted (Actual): March 30, 2026

Study Record Updates

• Last Update Posted (Actual): March 30, 2026
• Last Update Submitted That Met QC Criteria: March 26, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: ventricular arrhythmia; ventricular tachycardia; ventricular fibrillation; acute myocarditis
• Additional Relevant MeSH Terms: Cardiac Conduction System Disease; Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Tachycardia; Pathological Conditions, Signs and Symptoms; Tachycardia, Ventricular; Ventricular Fibrillation
• Other Study ID Numbers: 2025-137

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: The data that support the findings of this study will be available from the corresponding author, Miloud M. CHERBI, upon reasonable request.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No