Myocardial Injury and Outcomes Following COVID-19 Vaccination (MYOVAX Study) (MYOVAX)

April 21, 2026 updated by: University Health Network, Toronto
The study will focus on cardiac blood and imaging biomarkers to facilitate early recognition of patients at risk for myocardial injury after COVID-19 vaccination. Ultimately, the intention is to identify patients at risk, reduce adverse events, and determine the need for longer-term follow-up in patients with myocardial injury after vaccination.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

Coronavirus disease 2019 (COVID-19) vaccination frequently leads to minor side effects that may be more intense after the second dose, including fatigue and pain. However, there are emerging reports of more serious side effects in a minority of patients including myocarditis. Given the recent introduction of COVID-19 vaccination, there is limited understanding of: (i) prevalence and pattern of myocardial injury post vaccination, (ii) the risk factors for myocardial injury and adverse cardiac events post vaccination, and (iii) imaging and blood biomarkers for early recognition of patients at risk of adverse outcomes.

This study will address the above-mentioned knowledge gaps by focusing on patients who have received at least one dose of a COVID-19 vaccine. The study will focus on cardiac blood and imaging biomarkers to facilitate early recognition of patients at risk for myocardial injury after COVID-19 vaccination. Ultimately, the intention is to identify patients at risk, reduce adverse events, and determine the need for longer-term follow-up in patients with myocardial injury after vaccination.

Study Type

Interventional

Enrollment (Actual)

57

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Ontario
      • Toronto, Ontario, Canada, M5G 2C4
        • University Health Network

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

17 years and older (Child, Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Age ≥ 17 years (both Cohort A and B)
  2. Received at least one dose of a COVID-19 vaccine in the past 6 months (both Cohort A and B)
  3. Developed new clinical signs or symptoms suggestive of myocarditis/myocardial injury within one month of COVID vaccine administration without other known cause (Cohort A, only)

Exclusion Criteria:

  1. Contraindications to cardiac PET/MRI
  2. Current history of COVID-19

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Cohort A - Symptomatic
Those with clinical findings suggestive of myocarditis/myocardial injury after COVID-19 vaccination
Diagnostic test: Cardiac PET/MRI
An imaging technique that combines the strengths of both MRI and PET into one comprehensive study. This technique allows for detailed myocardial tissue characterization with MRI (including assessment of myocardial edema and fibrosis) and metabolic changes (including myocardial inflammation).
Diagnostic test: Blood Biomarkers
Markers of cardiac damage, inflammation, circulating microRNA profiles, and COVID antibody levels will be evaluated in patients after COVID-19 vaccination.
Other: Cohort B - Asymptomatic
Those without signs or symptoms suggestive of myocarditis after COVID-19 vaccination
Diagnostic test: Cardiac PET/MRI
An imaging technique that combines the strengths of both MRI and PET into one comprehensive study. This technique allows for detailed myocardial tissue characterization with MRI (including assessment of myocardial edema and fibrosis) and metabolic changes (including myocardial inflammation).
Diagnostic test: Blood Biomarkers
Markers of cardiac damage, inflammation, circulating microRNA profiles, and COVID antibody levels will be evaluated in patients after COVID-19 vaccination.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Prevalence of myocardial inflammation on PET/MRI
Time Frame: 6months and 12months
The prevalence of myocardial inflammation on PET/MRI will be compared between symptomatic and asymptomatic patients
6months and 12months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Major adverse cardiac events (MACE)
Time Frame: 6months and 12months

Defined as a composite of:

  1. Arrhythmias - new atrial or ventricular arrhythmia

  2. Acute coronary syndrome

    1. Acute myocardial infarction
    2. Unstable angina requiring revascularization (PCI or CABG)
  3. Heart failure hospitalization
  4. Cardiovascular death
6months and 12months
Left ventricular dysfunction
Time Frame: 6months and 12months
Defined as Left Ventricular Ejection Fraction (LVEF) < lower limit of normal on MRI
6months and 12months
Myocardial edema
Time Frame: 6months and 12months
Defined as high T2 > upper limit of normal on MRI
6months and 12months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University Health Network, Toronto

Investigators

  • Principal Investigator: Kate Hanneman, MD, University Health Network, Toronto

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 5, 2021

Primary Completion (Estimated)

August 5, 2026

Study Completion (Estimated)

August 5, 2026

Study Registration Dates

First Submitted

June 29, 2021

First Submitted That Met QC Criteria

July 16, 2021

First Posted (Actual)

July 20, 2021

Study Record Updates

Last Update Posted (Actual)

April 24, 2026

Last Update Submitted That Met QC Criteria

April 21, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 21-5621

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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