Rationale and design of the Pre-MYO project: a precision-medicine platform for myocarditis diagnosis and management

Abstract

Introduction

Myocarditis is an inflammatory disease characterized by a wide spectrum of clinical presentations, which complicates its diagnosis and management. The Precision Biomarkers for Diagnosis and Management of Myocardial Inflammatory Diseases (Pre-MYO) project aims to address three major gaps: (i) the limited knowledge regarding the epidemiology, clinical management and prognosis; (ii) the absence of specific and widely accessible biomarkers able to provide an early diagnosis (precision medicine); (iii) the lack of biomarkers of susceptibility to myocarditis, including risk of recurrence and disease severity (personalized medicine).

Study design

The Pre-MYO is a prospective, observational and multicentre nationwide project designed to enrol 3000 patients with suspected myocarditis or inflammatory cardiomyopathy based on clinical findings. The registry includes extensive clinical characterization and long-term follow-up, including biobanks of blood samples, DNA, and cardiac magnetic resonance imaging (CMR). The platform will enable the investigation and validation of novel diagnostic and prognostic biomarkers, including the candidate hsa-RNA-Chr8:96, and the development of clinical trials. Predisposition studies will be conducted to investigate environmental and immune factors, genetic mutations, and acquired variants—including methylation analyses—that contribute to individual predisposition and risk.

Discussion

The Pre-MYO project will establish a collaborative research framework aimed at improving the understanding and clinical management of myocarditis by integrating precision and personalized medicine approaches.

Graphical Abstract

Graphical Abstract.

Rationale

Burden of the disease

The term myocarditis refers to an inflammatory disease of the myocardium. In 2021, the global incidence of myocarditis was estimated at 1.3 million cases,¹ with prevalence varying across different population groups and diagnostic methodologies. Its burden is influenced by sociodemographic and environmental factors, including viral infections, toxins, and genetic predisposition. The disease predominantly affects young and middle-aged adults,¹ with a higher prevalence in males.² However, the true incidence of myocarditis is likely underestimated due to the diagnostic challenges associated with the condition. In recent years, the widespread implementation of high-sensitivity cardiac troponin assays has contributed to an increase in clinical suspicion of myocarditis, while the use of cardiac magnetic resonance imaging (CMR) has further improved diagnostic recognition. Indeed, hospital admissions for myocarditis have increased over the past decade and are expected to continue rising in the coming years.^3,4 As a consequence of the growing relevance of myocardial inflammatory disease, the European Society of Cardiology (ESC) has recently released the first Clinical Practice Guidelines for the management of myocarditis and pericarditis.⁵

Challenge of diagnosis

The clinical presentation of myocarditis is highly variable and lacks specific distinguishing features, aside from a compatible epidemiological history in some cases. Most patients present with chest pain resembling either coronary artery disease or pericarditis, while others report dyspnoea, fatigue, or palpitations. In some instances, myocarditis may first manifest as sudden cardiac death or acute heart failure. In addition to the absence of specific symptoms, there is also a lack of readily accessible diagnostic tests, complementary with existing troponins. Indeed, many patients are diagnosed late after other aetiologies have been excluded, typically after the exclusion of coronary artery disease in presence of elevated troponins or misdiagnosed in the absence of elevated troponins in triage. In this uncertain clinical scenario, a prompt diagnosis may facilitate clinical decisions based on the patient’s risk profile, in terms of monitoring, advanced studies and tailored therapies according to aetiologies.⁶ Furthermore, early diagnosis may help avoid unnecessary and potentially risky therapies and procedures, such as anticoagulants or invasive coronary angiography in patients with coronary like presentations.

Over the past decade, CMR has emerged as the most valuable non-invasive diagnostic tool for myocarditis, with the updated Lake Louise Criteria serving as the reference standard.^7,8 The integration of T1 and T2 mapping techniques has improved sensitivity to ∼88%, and it is now widely accepted that endomyocardial biopsy (EMB) is not always required to establish the diagnosis, although it remains necessary for guiding therapy in selected cases. ⁹ Indeed, the recently published guidelines relies the diagnosis on the presence of T1 and T2 criteria. However, access to CMR remains limited, particularly in community healthcare settings, and its diagnostic performance is time-dependent.^7,8,10–12 Consequently, despite its value, CMR is not always available for early diagnosis, especially outside specialized centres. As a result, many cases of myocarditis remain unconfirmed, with significant implications for both patients and their families.

Therefore, there is an urgent need for novel diagnostic tools that combine precision and early detection across diverse clinical settings.

Circulating biomarkers of myocarditis: hsa-RNA-Chr8:96

The biomarker hsa-RNA-Chr8:96 has been proposed as a candidate for incorporation into clinical practice following promising results from an initial derivation study. The murine biomarker mmu-miR-721 was originally identified through microarray analysis of Th17 cells and plasma from mice with autoimmune and viral myocarditis. Subsequent cloning of a consensus sequence from plasma samples of patients with acute myocarditis led to the identification of its human homologue, hsa-RNA-Chr8:96. This biomarker has been observed to be overexpressed by human Th17 cells and is detectable in plasma during the acute phase of myocarditis.¹³ Hsa-RNA-Chr8:96 demonstrated strong discriminatory performance in distinguishing acute myocarditis from other clinical conditions. In a validation cohort, it differentiated acute myocarditis (n = 151, confirmed by CMR or EMB) from healthy controls (n = 80), ST-elevation acute coronary syndromes (n = 105), non-ST elevation acute coronary syndromes (n = 45), myocardial infarction with normal coronary arteries (n = 20), and Th17-mediated autoimmune diseases without cardiac involvement (n = 152).¹³ Moreover, quantitative PCR analysis of hsa-RNA-Chr8:96 demonstrated a superior diagnostic accuracy for acute myocarditis compared to the elevation of conventional cardiac injury markers (troponins), highlighting its potential as an early diagnostic tool. The area under the curve for discriminating acute myocarditis from acute myocardial infarction was 0.927 (95% confidence interval, 0.879–0.975), and this performance remained robust after adjustment for potential confounders, including troponin levels, ejection fraction, age, and sex. The relative expression threshold of 6.9 (log₂ scale) was obtained as the optimal cut-off for distinguishing myocarditis from control groups, including patients with acute myocardial infarction, systemic autoimmune diseases without cardiac involvement, and healthy individuals. This threshold yielded a sensitivity of 87.5% and specificity of 96.2% in the validation cohort. Therefore Hsa-RNA-Chr8:96 represents a unique opportunity to improve the diagnosis of myocarditis and could be translated into clinical practice to enhance patient care and healthcare resource utilization. However, no prospective clinical validation of this biomarker has been carried out yet.

Nevertheless, several other miRNAs (such as miR-1, −133, −21, −15, −98, −126, −155, −148, −203, −208, −221, −222, −203, −500b-5p, and −590 among others) have been shown to be involved in the pathophysiology of viral myocarditis and some of them have been shown to have diagnostic abilities. In addition, they might participate actively in the disease and serve as prognostic biomarkers informing of risk or severity during the clinical course.^14,15

Individual susceptibility as a personalized approach

A key aspect of myocarditis is the individual susceptibility that underlies predisposition to the disease. Myocarditis is a multifactorial condition, and its clinical variability and prognosis may be influenced by a combination of factors, including genetic susceptibility, environmental exposures, and sociodemographic variables.¹⁶ In addition, although viral infections are the most frequently identified cause of myocarditis, the underlying aetiology remains undetermined in the majority of cases.¹⁷

Genetic predisposition plays a crucial role in myocardial inflammation, with both inherited and acquired variants contributing to susceptibility and disease progression. Previous studies investigating genetic variants associated with myocarditis have been limited by small sample sizes⁶; thus, larger population studies are required to identify inherited variants of significance in this context. Given the complexity of the disease and the heterogeneity in susceptibility and prognosis, it is unlikely that a single genetic variant will account for the observed variability. Polygenic risk scores (PRS) have therefore been proposed as a means to stratify individuals based on their cumulative genetic risk for developing myocarditis or experiencing adverse outcomes.¹⁸ In addition, acquired somatic mutations that drive the clonal expansion of haematopoietic stem cells are emerging as a novel risk factor for cardiovascular disease.¹⁹ This phenomenon, termed clonal haematopoiesis of indeterminate potential (CHIP) results in the transmission of the driver mutation to differentiated immune cells, and has been associated with a significantly increased risk of cardiovascular disease,²⁰ heightened inflammatory responses,²¹ and adverse progression of cardiomyopathy.²² Furthermore, recent evidence from the UK Biobank supports CHIP as risk factor for incident myocarditis among middle-aged adults.^16,20,23 However, the potential contribution of CHIP to myocarditis pathogenesis has not been fully elucidated. Mosaic loss of the Y chromosome (mLOY) in blood has also been implicated in promoting myocardial injury dysfunction and fibrosis.²⁴ The greater susceptibility of males to myocarditis, together with emerging evidence linking mLOY to cardiac disease, supports the hypothesis that mLOY may contribute to sex-related difference in myocarditis, which remains untested.

Among intra-individual factors associated with myocarditis risk and severity, variations in the immune system may also determine the individual susceptibility of cardiotropic infections, in particular T cells, Th17 cells, and regulatory T cells (Tregs), are key immune players in viral myocarditis, with CCL3 proposed as a novel biomarker for the condition.²⁵ Immune profiling plays central roles in shaping the inflammatory response and may influence disease severity, progression, and resolution. On the other hand, external factors as geographic and environmental influences should also be considered. Indeed, geographic and seasonal clustering of cases has been observed, likely reflecting the contribution of environmental or epidemiological factors.^3,26 Accordingly, these knowledge gaps underscore the critical need for further research to elucidate the complex mechanisms underlying myocarditis susceptibility.

Gaps to cover

The Precision Biomarkers for Enhanced Management of Myocardial Inflammatory Diseases (Pre-MYO) project seeks to address three major gaps in the field of myocarditis: (i) the limited knowledge regarding the epidemiology, burden, and clinical management of the disease; (ii) the absence of widely accessible and reliable diagnostic tools capable of enabling early and accurate diagnosis (precision medicine); (iii) the lack of individualized biomarkers that can identify susceptibility to myocarditis, including risk of recurrence and disease severity (personalized medicine).

Methods

Project design

The Pre-MYO project aims to establish a long-term platform for the comprehensive investigation of this disease. The central component is a large network of collaborating centres responsible for generating the study population, supported by two co-ordinating centres overseeing project management, data collection, biobanking, and data analysis.

Objectives

The primary objective of the Pre-MYO project is to advance the understanding of myocarditis and inflammatory cardiomyopathy, thereby facilitating the development of precision and personalized medicine approaches to improve clinical management. The specific objectives are as follows:

• To establish a large prospective cohort of patients with clinical suspicion and confirmed diagnosis of myocarditis.

• To create an extensive biobank comprising blood samples and centrally analysed CMR imaging from patients with an established diagnosis of myocarditis that enable to investigate and validate new biomarkers.

• To evaluate whether the determination of circulating hsa-RNA-Chr8:96 enhances the diagnostic accuracy for myocarditis.

• To analyse socioeconomic and environmental factors contributing to the development of myocarditis.

• To identify both acquired and inherited genetic mutations in patients with myocarditis or inflammatory cardiomyopathy, and to assess their association with disease susceptibility, severity, and therapeutic response.

• To investigate sex-specific differences in myocarditis, including potential underdiagnosis in women and the exploration of protective pathophysiological mechanisms.

• To establish a collaborative network platform that enables to develop future research, including clinical trials.

Generation of a collaborative network

The Pre-MYO network is a national, multicentre initiative comprising two co-ordinating centres (IMIB and CNIC) and more than 70 participating sites distributed throughout Spain. These include large tertiary care centres as well as smaller regional hospitals, thereby ensuring a broad, diverse, and representative patient population. This structure allows the project to address potential disparities in healthcare access and diagnostic capacity across different regions.

Generation of a large study cohort

The Pre-MYO cohort is a prospective, observational, multicentre clinical registry that aims to enrol 3000 patients with suspected myocarditis or inflammatory cardiomyopathy based on routine clinical practice findings (Figure 1). Patients are eligible for inclusion in the Pre-MYO cohort if they are over 2 years old and they present with at least one compatible clinical symptom and one objective diagnostic test suggestive of myocarditis, in accordance with the ESC consensus and guidelines^5,10 (Table 1). The study is registered with ClinicalTrials.gov, NCT06898762.

Figure 1.

Study flow diagram for the establishment of the Pre-MYO cohort and related studies

Table 1.

Inclusion criteria of Pre-MYO cohort

Clinical presentation (at least one)

Acute chest pain: pericardial or pseudo-ischaemic.

Dyspnoea or other symptoms/signs of heart failure.

Palpitations/arrhythmias, recovered sudden death.

Cardiogenic shock.

Diagnostic findings (at least one)

ECG: new-onset AV block, new-onset bundle branch block, ST segment elevation/decrease, T wave inversion.

Elevated troponin I (TnI) or troponin T (TnT).

Segmental or global contractility abnormalities not explained by other causes.

Positive Lake Louise criteria on cardio MRI4

ECG, electrocardiogram; AV, atrioventricular; TnI, troponin I; TnT, troponin T; MRI, cardiac magnetic resonance imaging.

Data collection based on Clip-Pre-MYO development

The flow of recruitment, data collection and management is shown in Figure 1. A user-friendly digital platform (Clip-Pre-MYO) has been developed to enable rapid patient enrolment by local investigators and document upload from recruiting centres, including mobile devices. After providing informed consent and meeting eligibility criteria, patients are enrolled through the Clip-Pre-MYO API, which assigns a unique study code to ensure pseudonymization. Local investigators upload clinical reports through the platform. Data are managed centrally at the co-ordinating centre, that is responsible of reviewing, anonymizing and enter the data into the electronic case report form, using standardized questionnaires and uploaded medical documents. All data are subsequently standardized and integrated into a central research repository, facilitating statistical analyses aligned with the project’s objectives and supporting the design of future sub-studies.

Follow-up

Patient follow-up is coordinated centrally and conducted via telephone. One month after enrolment, patients are contacted to collect clinical and epidemiological data (Figure 1). Follow-up assessments are performed every six months for up to three years to update information on vital status, symptom recurrence, and major cardiovascular events. The pragmatic design allows seamless integration of the study into routine clinical practice.

Biobanks

During the baseline visit, blood samples are collected for molecular analyses and biobanking (Figure 3). Biological specimens, including venous whole blood, serum, plasma, RNA, and peripheral blood cells, are processed at local biobanks according to standardized protocols. Samples are temporarily stored at −80°C at the recruiting centres before being transported under controlled conditions to the central biobank, the Biobanco en Red de la Región de Murcia (PT17/0015/0038), which is integrated into the Spanish National Biobanks Network (B.000859). In addition, for patients who undergo EMB as part of routine clinical practice, a network of local biobanks will be established to store both paraffin-embedded and fresh myocardial specimens. Based on current ESC 2025 guideline indications for EMB, we estimated that about 10% of patients would meet these criteria; accordingly, ∼150 patients would have available biopsy specimens.

CMR imaging files will be collected in DICOM format and uploaded to a virtual centralized platform, in order to establish a dedicated CMR biobank. An independent imaging committee will be dedicated within the project and a central core lab will be set up, that will be in charge of quality review, reading and validation, and development of further specific research projects. As we are dealing with imaging data collected from clinical practice and different centres, the first step will be to harmonize the heterogeneity of vendors, by standardizing acquisition and processing, in order to ensure the quality and interpretation of CMR sequences.

Diagnosis review committee

An independent clinical committee has been established to review myocarditis diagnoses. Two experts will independently evaluate each case to assign a diagnosis of myocarditis. In cases of disagreement, a third clinical expert will review the case to reach a final consensus. In addition, deaths and reported events within the study will be reviewed by this committee. The diagnosis of myocarditis is classified into three categories, in accordance with the recommendations of the ESC25 guidelines⁵:

• Definite myocarditis: clinical presentation with additional supportive findings and meeting diagnostic criteria by CMR (both T1 and T2 criteria) or by EMB.

• Probable myocarditis: clinical presentation with additional supportive findings, but CMR and EMB uncertain or not available.

• Unlikely/rejected myocarditis: only clinical presentation, without additional criteria.

The diagnosis of inflammatory cardiomyopathy is established when chronic myocarditis (>3 months) is present in association with cardiac dysfunction and ventricular remodelling, with clinical phenotype of hypokinetic, either dilated or non-dilated cardiomyopathy with/without arrhythmogenic substrate.

The aetiologic diagnosis will be defined according to current international guidelines.^5,9,17 In patients undergoing EMB, aetiology will be established by integrating tissue findings—including histology, quantitative immunohistochemistry, and molecular testing for cardiotropic viral genomes—with clinical data. In patients without EMB, the etiologic diagnosis will be classified as presumptive, based on clinical presentation, imaging findings, and ancillary tests.

Search and validation of new biomarkers for diagnosis

Hsa-RNA-Chr8:96 was chosen as a leading biomarker candidate based on prior work from the group.¹³ The validation of this candidate biomarker will be conducted in two phases. First, the blood samples collected from the established cohort of patients with suspected myocarditis will be analysed in order to re-evaluate and refine the predefined diagnostic threshold of Hsa-RNA-Chr8:96 expression. The specific procedures for Hsa-RNA-Chr8:96 assessment are described in detail in the Supplementary material. The results will be compared with the final diagnosis assigned by the diagnosis adjudication committee, in a blinded manner. This analysis will provide a definitive diagnostic threshold and evidence regarding the diagnostic performance and accuracy of Hsa-RNA-Chr8:96. The definitive validation will require of an interventional clinical trial comparing standard clinical practice with the biomarker-assisted diagnosis in terms of: time to definitive diagnosis, rate of unnecessary therapies and procedures (e.g. anticoagulants or coronary angiography) and clinical adverse events.

The stored samples will enable to explore and validate other biomarker candidates. In particular several microRNA have been shown to be altered and/or involved in the pathophysiology of myocarditis, and other have been proposed as diagnostic or prognostic candidates. The project aims to serve as platform to study those previously described and emerging scientific evidence, such as exosomal microRNAs and autoantibodies, RNA sequencing and other -omics technologies may be applied to stored biological materials to facilitate unbiased discovery and validation of novel biomarkers.

Identification of individual predisposition determinants

The Pre-MYO cohort offers a robust epidemiological platform through its comprehensive clinical registry, enabling researchers to investigate the impact of sex and age on the pathophysiology and clinical management of myocarditis. Single nucleotide polymorphism (SNP) genotyping arrays and targeted DNA sequencing will be performed on samples from the Pre-MYO Cohort to identify genetic variants in a large population. The gene panel for analysis will include genes previously associated with myocarditis and other cardiomyopathies, as well as genes involved in immunomodulatory pathways, incorporating both inherited and acquired variants such as somatic mutations associated with CHIP and quantification of mLOY. Blood DNA methylome will also be analysed to investigate individual susceptibility to the disease and to assess the potential of these biomarkers for disease prognosis. Methylation profiling will further allow characterization of the exposome and lifestyle factors in individuals enrolled in the Pre-MYO cohort. Finally, penalized regression models (elastic net) will be applied to evaluate whether incorporating the molecular features identified in this study (PRS, CHIP, mLOY, methylation marks) can enhance the prognostic and diagnostic performance of hsa-RNA-Chr8:96, particularly in specific subgroups of clinical interest.

Immune profiling is essential to understand individual susceptibility to cardiotropic infections and the pathophysiology of viral myocarditis. To address this, the Pre-MYO project includes a dedicated immunophenotyping work package. Specifically, we will perform multiparametric flow cytometry to characterize peripheral immune cell subsets in patients with acute myocarditis, including: quantification of Th17 cells, identified by intracellular IL-17 staining following 18 h anti-CD3 stimulation and a 4 h PMA/ionomycin/brefeldin A incubation protocol; characterization of regulatory T cell subsets, including naïve (CD4⁺ CD25⁺ FOXP3⁺ CD45RA⁺ CD45RO⁻) and memory (CD4⁺ CD25⁺ FOXP3⁺ CD45RA⁻ CD45RO⁺) Tregs and assessment of spontaneous apoptosis in cultured Treg populations. All samples will be analysed using a FACSymphony flow cytometer and processed with FlowJo v10.0.4 software. This approach will allow us not only to map immune alterations in myocarditis patients compared to healthy controls, but also to explore candidate immune biomarkers such as CCL3. Moreover, to determine whether these findings accurately reflect the immunological milieu within the myocardium, immune cell characterization will also be performed on the available EMB specimens.

Ethics

The study protocol was approved by the local ethics committee of the co-ordinating centre and subsequently validated by the Research Ethics Committees of all participating centres. The study is conducted in accordance with the principles outlined in the Declaration of Helsinki, and written informed consent was obtained from all participants prior to enrolment.

Statistical plan and bioinformatics

An expanded description of statistical plan is included as Supplementary material. The cohort aims to enrol 3000 patients with suspected myocarditis in order to achieve a sample size of 1000–1500 confirmed cases, considering that 35–50% of participants will receive a confirmed diagnosis of myocarditis. This sample size ensures adequate precision for estimates of sensitivity and specificity of the novel biomarkers under evaluation. Multivariate statistical analyses will be performed to identify potential associations between genetic variants, PRS, inherited mutations, and key methylation markers related to environmental and lifestyle factors. Mendelian randomization analyses will be conducted to infer causal relationships between demographic or socio-environmental factors and biomarker expression, leveraging SNP array data to explore potential causal mechanisms. This approach aims to elucidate the biological pathways underlying the specific expression of biomarker dysregulation in myocarditis patients, thereby providing insights for the development of potential prognostic strategies. A similar analytical framework will be applied to investigate exposome-related variables associated with specific immune cell populations in patients with myocarditis. To develop a novel predictor of myocarditis risk, molecular and exposome data will be integrated. Subgroup analyses will be conducted to evaluate the specificity and sensitivity of biomarkers in minority subgroups, such as female patients. Sensitivity analyses will assess whether the absence of CMR or differences between centres in access to this test may influence case classification. These analyses will test the robustness of the results under different diagnostic assumptions. Sex-specific analyses and additional methodological details, including diagnostic accuracy, genomic and causal inference analyses, are provided in the Supplementary Statistical Materials. Furthermore, penalized regression models (elastic net) with automated feature selection will be employed to assess whether incorporating molecular features identified in this study—including PRS, CHIP, mLOY, and key methylation markers—can enhance the predictive capacity of biomarkers.²⁷ The integration of molecular and clinical data generated in this study will deepen our understanding of myocarditis pathophysiology and contribute to the development of novel clinical prevention and prognostic strategies. All analyses will be performed using R (v.4.4.2) and Python (v.3.11).

Discussion

The results of the Pre-MYO project are expected to substantially advance our understanding of myocarditis by establishing a stable collaborative research platform, incorporating a biobank for blood samples and a repository for diagnostic imaging data. This platform will enable future studies aimed at identifying novel biomarkers and genetic mutations, as well as facilitating research on CMR imaging, environmental exposures, and sociodemographic factors associated with increased disease susceptibility and prognosis. The findings may ultimately contribute to the development of precision interventions and personalized prevention strategies (Graphical Abstract).

The Pre-MYO cohort aims to become the largest prospective cohort of patients with suspected myocarditis. To date, most existing studies are limited to retrospective registries or prospective cohorts of myocarditis with less than 1000 patients^3,26 (Table 2). Population based data shown growing incidence rate,^3,26 with a reported annual incidence of 7.8 per 100 000 inhabitants in 2022 in Germany.³ In Europe, the ‘Global Burden of Disease’ study retrieved data from 1991 to 2020, confirming that the global incidences and deaths of myocarditis have significantly increased.¹ Although incidence rate is higher in male, in-hospital mortality and complications seems higher in female patients.²⁸ The Pre-MYO cohort will provide extensive patient characterization, incorporating clinical, sociodemographic, genetic, and environmental data, alongside a biobank of blood samples and an imaging biobank of diagnostic studies. Other ongoing international registries include the AMPHIBIA cohort in France (ClinicalTrials.gov ID: NCT04844151), which aims to characterize the histological, immunological, biological, imaging, genetic, and clinical features of patients hospitalized with confirmed acute myocarditis, and to evaluate their association with patient outcomes. Furthermore, the FORWARD cohort (ClinicalTrials.gov ID: NCT06010199) seeks to collect clinical data and biological specimens from myocarditis patients to develop predictive models of prognosis based on biomarker profiles.

Table 2.

Summary of worldwide registry studies on myocarditis

NCT number	Registry	Time	Study design (years)	Country	Ages	Condition	Sample size	Biological samples	Follow-ups
NCT04498494	The Role of Electrocardiograms in Risk Stratification and Analysis of the Characteristics of ST Elevation in Acute Myocarditis	Retrospective	Case-Control (2007–2019)	China	≥13 years	Acute myocarditis	274	Unknown	2 years
NCT04304118	Rajaie Cardiomyopathy and Myocarditis Registry	Prospective	Patient Registry (2019–2025)	Iran	1 Year and older	Myocarditis	6000	Unknown	12 Months
NCT04844151	Acute Myocarditis Registry With Prognostic, Histologic, Immunologic, Biological, Imaging and Clinical Assessment (AMPHIBIA)	Retrospective and prospective	Patient Registry (2006–2041)	France	15 Years and older	Acute myocarditis	1400	Samples With DNA, Whole blood 20ml	20 Years
NCT05933902	Multicenter Retrospective Observational Study of Acute Myocarditis in Korea	Retrospective	Cohort (2001–2021)	Korea	Children and adults	Acute myocarditis	841	Unknown	1 year
NCT04827706	Nationwide MYO-PL database28	Retrospective and prospective	Cohort (2009–2020)	Poland	Children and adults	Myocarditis	19 978	Unknown	Unknown
NCT02717143	French National Observatory Tracking Viral Myocarditis: Mortality, Cardiovascular Events, Sequels on (Magnetic Resonance Imaging) MRI (MYOCARDITIRM)	Prospective	Cohort (2016–2021)	France	18 Years and older	Acute myocarditis	821	Unknown	3 years
NCT05949450	PROGNOSTIC	Retrospective and prospective	Cohort (2016–2025)	France	18 Years and older	Myocarditis	244	Unknown	4 years
NCT05139329	The ORCHESTRATE-Myocarditis Registry	Retrospective	Cohort (2014–2022)	United States	18 Years and older	Presentation Of atypical chest pain and following A negative ischaemic evaluation	382	Unknown	Unknown
NCT06010199	Risk Stratification Value of Biomarkers in Patients With Myocarditis (FORWARD)	Retrospective and prospective	Cohort (2023–2030)	China	3 Years to 80 Years	Myocarditis	1000	Samples With DNA, Blood, urine, faeces.	Unknown
NCT04375748	MYOCOVID	Prospective	Cohort (2020–2021)	France, Martinique, Mayotte and Réunion	Children and adults	Acute myocarditis	756	Unknown	1 year
—	Taiwan nationwide registry29	retrospective	Patient registry (2000–2004)	Taiwan	18 years and older	Myocarditis	13 250	Unknown	11 years
—	Multicenter Lombardy Registry26	Retrospective	Patient Registry (2001–2017)	Italy	Less than 70 years	Clinically suspected myocarditis	684	Unknown	Up to 16 years
NCT02970227	Inflammatory Cardiomyopathy Baseline Cohort (SFB/TR19) (SFB/TR19)	Prospective	Patient Registry (2004–2015)	Germany	18 Years and older	Inflammatory cardiomyopathy	920	Unknown	12 Years
NCT04774549	Inflammatory Cardiomyopathy Bern Registry (FlamBer)	Prospective	Patient Registry (2005–2026)		18 Years and older	Inflammatory cardiomyopathy	1125	Unknown	5 Years
—	ITalian multicenter study on Acute Myocarditis (ITAMY)30	Prospective	Patient registry (2006–2014)	Italy	Children and Adults	Acute myocarditis	543	Unknown	8 years
—	NIS database31	Retrospective	Patient registry (2007–2014)	United States	18 years and older	Myocarditis	27 129	Unknown	Unknown
—	German nationwide registry3	Retrospective	Patient registry (2007–2022)	Germany	18 Years and older	Myocarditis	88 159	Unknown	Unknown
NCT02187263	German Centre for Cardiovascular Research Cardiomyopathy Register (TORCH)	Prospective	Patient Registry (2014–2017)	Germany	18 Years to 79 Years	Inflammatory cardiomyopathies	2300	Samples With DNA, EDTA, serum, urine	12 Months
NCT02590341	Myocarditis Registry for Children and Adolescents—MYKKE (MYKKE)	Prospective	Patient Registry (2014–2024)	Germany	Up to 17 Years	Myocarditis	1500	Unknown	10 Years
NCT04521790	MYOCAR	Retrospective and prospective	Patient Registry (2018–2035)	Italy	18 Years and older	Clinically suspected myocarditis	1000	Unknown	10 Years

The Pre-MYO cohort follows a pragmatic design that enables participation by a large number of centres, ensuring a diverse and representative patient population. The involvement of a broad hospital network will provide valuable insights into real-world patient management and contribute to disseminate national clinical guidelines and consensus documents. An additional strength of Pre-MYO is the inclusion of both confirmed and suspected (but not yet confirmed) myocarditis cases, thereby offering a more comprehensive understanding of the disease spectrum, from initial suspicion to confirmed diagnosis. To facilitate patient recruitment and follow-up, a user-friendly application (Clip-Pre-MYO) has been developed. This system represents a strength that enables rapid enrolment, centralized data management and improved recruitment rates, while minimizing disruptions to routine clinical care.

Although hsa-RNA-Chr8:96 has been selected as the index biomarker for initial validation, Pre-MYO platform is not limited to a single biomarker but is intended to support broad biomarker discovery and validation efforts in myocarditis. The Pre-MYO platform incorporates a biobank specifically designed to enable future analyses of additional candidate biomarkers, including exosomal microRNAs and autoantibodies, by using targeted assays or unbiased approaches such as RNA sequencing and other omics. Pre-MYO aims to generate clinical evidence that may inform clinical decision-making in patients with suspected myocarditis through the validation of novel diagnostic biomarkers. Hsa-RNA-Chr8:96 is a promising biomarker with the potential to improve diagnostic accuracy, reduce the need for invasive procedures, and optimize healthcare resource utilization during patient management.¹²

The identification of factors underlying individual susceptibility to myocarditis remains an unmet clinical need. The Pre-MYO study aims to advance the understanding and prediction of myocarditis susceptibility through a comprehensive multi-omics approach. This study will integrate exposome-related variables, environmental and lifestyle exposures, with immune cell population data. This approach recognizes that immune responses in myocarditis are likely driven by a complex interplay between genetic predisposition and environmental triggers. The inclusion of molecular variables such as CHIP, mLOY, PRS, and key methylation markers reflects both the depth and innovation of this strategy. These features have been increasingly implicated in cardiovascular disease, and we anticipate that their incorporation will enhance risk prediction for myocarditis within the Pre-MYO cohort. Moreover, this integrative approach holds the potential to enable more personalized preventive strategies for patients at risk of myocarditis.

Among the limitations, we acknowledge that data collection is restricted to routine clinical practice, which may result in the absence of laboratory test values that are not routinely ordered, thereby increasing the potential for missing data within the registry. Additionally, heterogeneity in diagnostic approaches across participating hospitals—particularly regarding access to advanced imaging modalities such as CMR—may lead to variability in the accuracy and standardization of myocarditis diagnosis. Furthermore, patient enrolment is voluntary, which may introduce selection bias, as individuals included in the cohort may not fully represent the broader myocarditis population. However, capturing heterogeneity is crucial to better understand disease management and evolution. Finally, Pre-MYO was designed as a nationwide project, which will limit generalizability and, consequently, the level of genetic and exposure diversity is limited. Nevertheless, we intend to disseminate and expand the project to other European centres in the future.

Conclusion and future directions

The Pre-MYO project aims to make a significant contribution to the understanding and management of myocarditis by addressing key existing gaps—particularly by improving diagnostic accuracy and identifying personalized markers of susceptibility. In addition, it will establish a large-scale platform of clinical data and biobanked materials, including blood samples and CMR imaging data, which will serve as a valuable resource for future research. Their results may enhance the precision of diagnosis, and to facilitate personalized strategies. Nevertheless, it may represent a platform ready to be used for future studies including multimodal or AI-based models.

Author contributions

Domingo A Pascual-Figal (Conceptualization; Funding acquisition; Investigation; Methodology; Project administration; Supervision; Visualization; Writing—original draft; Writing—review & editing), Belén Álvarez Álvarez (Investigation; Writing—review & editing), Juan Fernández-Martínez (Investigation; Writing—review & editing), Marcelo Sanmartin-Fernandez (Investigation; Writing—review & editing), Héctor Bueno (Investigation; Writing—review & editing), José María Viéitez Flórez (Investigation; Writing—review & editing), Carles Diez-Lopez (Investigation; Writing—review & editing), Pablo Pastor-Pueyo (Investigation; Writing—review & editing), Antonia Tercero Martinez (Investigation; Writing—review & editing), Silvia Lopez-Fernandez (Investigation; Writing—review & editing), Angel Manuel Iniesta-Manjavacas (Investigation; Writing—review & editing), Aitor Uribarri-González (Investigation; Writing—review & editing), Fátima Sánchez-Cabo (Conceptualization; Funding acquisition; Investigation; Methodology; Writing—review & editing), Pilar Martín (Conceptualization; Funding acquisition; Investigation; Methodology; Writing—review & editing), José J. Fuster (Conceptualization; Funding acquisition; Investigation; Methodology; Writing—review & editing), Angel Esteban-Gil (Conceptualization; Funding acquisition; Methodology; Software), Azahara M García-Serna (Project administration; Visualization; Writing—original draft; Writing—review & editing), Jose M Larrañaga-Moreira (Investigation; Writing—review & editing), and Fernando Domínguez (Conceptualization; Funding acquisition; Investigation; Methodology; Writing—original draft; Writing—review & editing).

Supplementary data

Supplementary data are available at ESC Heart Failure online.

Declarations

Disclosure of Interest

All authors declare no disclosure of interest for this contribution.

Data Availability

No new data were generated or analysed in support of this research.

Funding

This work has been funded by the Instituto de Salud Carlos III (ISCIII) through the project ‘PMP22/00105’ and funded by the European Union through the NextGeneration EU Recovery, Transformation and Resilience Plan.