132 PREVALENCE CHARACTERISTICS AND OUTCOMES OF COVID 19 ASSOCIATED ACUTE MYOCARDITIS
Authors: Palazzini Matteo , Lupi Laura , Ammirati Enrico , Giannattasio Cristina , Soriano Francesco , Pedrotti Patrizia , Briguglia Daniele , Mapelli Massimo , Campodonico Jeness , Agostoni Piergiuseppe , Leonardi Sergio , Turco Annalisa , Guida Stefania , Peretto Giovanni , Sala Simone , Camici Paolo G , Marzo Francesca , Grosu Aurelia , Senni Michele , Turrini Fabrizio , Bramerio Manuela , Marini Marco , Matassini Maria Vittoria , Rizzo Stefania , Basso Cristina , De Gaspari Monica , Hendren Nicholas S , Schmidt Matthieu , Bochaton Thomas , Piriou Nicolas , Ubarri Aitor , Van De Heyning Caroline , Sole Albert Ariza , Cannatà Antonio , Salamanca Jorge , Lehtonen Jukka , Huang Florent , Adler Eric D , Metra Marco 
Published: December 2022

Abstract

Background
Acute myocarditis (AM) is thought to be a rare cardiovascular complication of COVID-19, although minimal data are available beyond case reports. We aim to report the prevalence, baseline characteristics, in-hospital management, and outcomes for patients with COVID-19–associated AM on the basis of a retrospective cohort from 23 hospitals in the United States and Europe.

Methods
A total of 112 patients with suspected AM from 56963 hospitalized patients with COVID-19 were evaluated between February 1, 2020, and April 30, 2021. Inclusion criteria were hospitalization for COVID-19 and a diagnosis of AM on the basis of endomyocardial biopsy or increased troponin level plus typical signs of AM on cardiac magnetic resonance imaging. We identified 97 patients with possible AM, and among them, 54 patients with definite/probable AM supported by endomyocardial biopsy in 17 (31.5%) patients or magnetic resonance imaging in 50 (92.6%). We analyzed patient characteristics, treatments, and outcomes among all COVID-19–associated AM.

Results
AM prevalence among hospitalized patients with COVID-19 was 2.4 per 1000 hospitalizations considering definite/probable and 4.1 per 1000 considering also possible AM. The median age of definite/probable cases was 38 years, and 38.9% were female. On admission, chest pain and dyspnea were the most frequent symptoms (55.5% and 53.7%, respectively). Thirty-one cases (57.4%) occurred in the absence of COVID-19–associated pneumonia. Twenty- one (38.9%) had a fulminant presentation requiring inotropic support or temporary mechanical circulatory support. The composite of in-hospital mortality or temporary mechanical circulatory support occurred in 20.4%. At 120 days, estimated mortality was 6.6%, 15.1% in patients with associated pneumonia versus 0% in patients without pneumonia (P=0.044). During hospitalization, left ventricular ejection fraction, assessed by echocardiography, improved from a median of 40% on admission to 55% at discharge (n=47; P&lt;0.0001) similarly in patients with or without pneumonia. Corticosteroids were frequently administered (55.5%).

Conclusions
AM occurrence is estimated between 2.4 and 4.1 out of 1000 patients hospitalized for COVID-19. The majority of AM occurs in the absence of pneumonia and is often complicated by hemodynamic instability. AM is a rare complication in patients hospitalized for COVID-19, with an outcome that differs on the basis of the presence of concomitant pneumonia.