The aim of this study is to assess the prevalence and arrhythmogenic role of occult myocardial scars on Cardiac Magnetic Resonance (CMR) in a population of patients with history of laboratory-proven symptomatic COVID-19 infection managed without hospitalization, as compared to a population of age- and sex-matched healthy volunteers.

Multiple large series conducted in hospitalized patients have reported high rates of myocardial injuries in the acute stage of COVID-19 infection. These findings have raised concerns regarding potential long term consequences of the pandemic on cardiovascular diseases (heart failure and sudden cardiac deaths due to scar-related arrhythmias). However, the prevalence of silent myocardial injuries in the general population who presented a COVID-19 infection managed without hospitalization are unknown. In addition, the propensity of these scars to generate arrhythmias have not been thoroughly studied. COVID CMR will include 120 patients with history of laboratory-proven symptomatic COVID-19 infection managed without hospitalization and 120 age- and sex-matched controls. At day 1, all subjects will undergo a 12-lead electrocardiogram, a contrast-enhanced CMR study including advanced methods to detect silent myocardial scars, and a blood sample to look for markers of inflammation and cardiac injury, and to assess the COVID-19 serological status at the time of the CMR study. The prevalence of myocardial scars on CMR will be compared between the 2 groups. In a second visit at 3 months, patients showing myocardial scar on CMR will be matched to healthy volunteers showing no such scars, and these 2 population subsets will undergo exercise electrocardiogram (ECG) and 24 hour Holter ECG to characterize the arrhythmogenic role of silent myocardial scars.

Inclusion Criteria:

• Man or woman ≥ 18 years old
• Affiliated to a health insurance program
• Providing free, informed, written and signed consent to participate (at the latest on the day of inclusion and before any research procedure is initiated)
• Effective contraception if women in the age to procreate
• In the patient group : history of COVID-19 infection with either a positive Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) test on nasopharyngeal swab or a positive COVID-19 serology in the acute stage. Presence of all following symptoms in the acute stage: fever>38°C, asthenia, arthromyalgia, associated with at least 2 of the following: coughing and/or spitting, dyspnea and/or chest discomfort, anosmia and/or ageusia.

Exclusion Criteria:

• age < 18 years old

• History of cardiac disease or acute coronary syndrome associated with troponin rise

• History of allergic reaction to gadolinium-based contrast agents

• History of severe renal failure

• Presence of a pacemaker, implantable defibrillator, intra-orbital metallic material, intra-cranial surgical clip, valve prosthesis Star-Edwards pre 6000, neurostimulator or implantable insulin pump

• Claustrophobia or inability to lay on the back for 50 min

• Pregnant or breast feeding women

• Inability to express informed consent

• Person deprived of liberty by judicial or administrative decision

• Person under legal protection

• In the healthy volunteer group:

  • Symptoms suggestive of COVID-19 infection over the epidemic period (after February 1st 2020)
  • Person not willing to be informed of potential incidental CMR findings

• In the patient group:

  • Hospitalization for infectious syndrome suggestive of COVID-19.