Fulminant myocarditis proven by early biopsy and outcomes
Authors: Huang Florent , Ammirati Enrico , Ponnaiah Maharajah , Montero Santiago , Raimbault Victor , Abrams Darryl , Lebreton Guillaume , Pellegrino Vincent , Ihle Joshua , Bottiroli Maurizio , Persichini Romain , Barrionuevo-Sánchez Marisa Isabel , Ariza-Solé Albert , Ng Pauline Yeung , Sin Simon Wai Ching , Ayer Raj , Buscher Hergen , Belaid Slimane , Delmas Clément , Ferreira Rita , Roncon-Albuquerque Roberto , López-Sobrino Teresa , Bunge Jeroen J H , Fisser Christoph , Franchineau Guillaume , McCanny Jamie , Ohshimo Shinichiro , Sionis Alessandro , Hernández-Pérez Francisco José , Barge-Caballero Eduardo , Balik Martin , Muglia Henrique , Park Sunghoon , Donker Dirk W , Porral Beatriz , Aïssaoui Nadia , Mekontso Dessap Armand , Burgos Virginia , Lesouhaitier Mathieu , Fried Justin , Jung Jae-Seung , Rosillo Sandra , Scherrer Vincent , Nseir Saad , Winszewski Hadrien , Jorge-Pérez Pablo , Kimmoun Antoine , Diaz Rodrigo , Combes Alain , Schmidt Matthieu ,   for the FULLMOON Study Group, Huang Florent , Kerneis Mathieu , Montalescot Gilles , Collet Jean Philippe , Delmas Clément , Belaid Slimane , Lavie-Badie Yoan , Biendel Caroline , Lesouhaitier Mathieu , Tadié Jean-Marc , Scherrer Vincent , Barge-Caballero Eduardo , Blanco-Canosa Paula , Grille-Cancela Zulaika , Porral Beatriz , Raposeiras Sergio , Rosillo Sandra , López-de-Sá Esteban , Sionis Alessandro , Hernando Víctor García , López-Sobrino Teresa , Riba Rut Andrea , Sandoval Elena , Burgos Virginia , Lera Marta Ruiz , Alvarez Angela Canteli , Bustamante Cristina Castrillo , Martínez Natalia Royuela , Martín Pablo Jorge-Pérez , García-González J , Martín-Cabeza Marta M , Miranda Dinis Reis , Bunge Jeroen J H , Caliskan Kadir , Fried Justin , Ching Simon Sin Wai , Jung Jae-Seung , Kim Jieon , Shin Hong Ju , Ohshimo Shinichiro , Kikutani Kazuya , Shime Nobuaki 
Published: November 2023

Abstract

Background and Aims
While endomyocardial biopsy (EMB) is recommended in adult patients with fulminant myocarditis, the clinical impact of its timing is still unclear.

Methods
Data were collected from 419 adult patients with clinically suspected fulminant myocarditis admitted to intensive care units across 36 tertiary centres in 15 countries worldwide. The diagnosis of myocarditis was histologically proven in 210 (50%) patients, either by EMB (n = 183, 44%) or by autopsy/explanted heart examination (n = 27, 6%), and clinically suspected cardiac magnetic resonance imaging confirmed in 96 (23%) patients. The primary outcome of survival free of heart transplantation (HTx) or left ventricular assist device (LVAD) at 1 year was specifically compared between patients with early EMB (within 2 days after intensive care unit admission, n = 103) and delayed EMB (n = 80). A propensity score-weighted analysis was done to control for confounders.

Results
Median age on admission was 40 (29–52) years, and 322 (77%) patients received temporary mechanical circulatory support. A total of 273 (65%) patients survived without HTx/LVAD. The primary outcome was significantly different between patients with early and delayed EMB (70% vs. 49%, P = .004). After propensity score weighting, the early EMB group still significantly differed from the delayed EMB group in terms of survival free of HTx/LVAD (63% vs. 40%, P = .021). Moreover, early EMB was independently associated with a lower rate of death or HTx/LVAD at 1 year (odds ratio of 0.44; 95% confidence interval: 0.22–0.86; P = .016).

Conclusions
Endomyocardial biopsy should be broadly and promptly used in patients admitted to the intensive care unit for clinically suspected fulminant myocarditis.