Cardiac MRI in Suspected Acute COVID-19 Myocarditis

Changes in subclinical cardiac abnormalities 1 Year after recovering from COVID-19 in patients without clinical cardiac findings

Aim

To evaluate the subclinical cardiac involvement in COVID-19 patients without clinical cardiac evidence using cardiac MR imaging.

Material and methods

Participants recovered from COVID-19 without cardiac symptoms and no cardiovascular medical history were enrolled in a prospective cohort study. They underwent baseline cardiac MR and follow-up cardiac MR > 300 days after discharge (n = 20). The study also included healthy controls (n = 20). Extracellular volume fraction (ECV), native T1, and 2D strain data were assessed and compared.

Results

The ECV values of participants at baseline [30.0% (28.3%-32.5%)] and at follow-up [31.0% (28.0%-32.8%)] were increased compared to the healthy control group [27.0% (25.3%-28.0%)] (both p < 0.001). However, the ECV increase from baseline cardiac MR to follow-up cardiac MR was not significant (p = 0.378). There was a statistically significant difference in global native T1 between baseline [1140 (1108.3-1192.0) ms] and follow-up [1176.0 (1113.0-1206.3) ms] (p = 0.016). However, no native T1 difference was found between the healthy controls [1160.7 (1119.6-1195.4) ms] and the baseline (p = 0.394) or follow-up group (p = 0.168). The global T2 was 41(40-42) ms at follow-up which was within the normal range. In addition, We found a recovery in 2D GLS among COVID-19 participants between baseline and follow-up [-12.4(-11.7 to -14.3)% vs. -17.2(-16.2 to -18.3)%; p＜0.001].

Conclusion

Using cardiac MR myocardial tissue and strain imaging parameters, 35% of people without cardiac symptoms or clinical evidence of myocardial injury still had subclinical myocardial tissue characteristic abnormalities at 300 days, but 2D GLS had recovered.

Right and left ventricular cardiac magnetic resonance imaging derived peak systolic strain is abnormal in children with myocarditis

PURPOSE

Cardiac Magnetic resonance (CMR) derived left ventricular longitudinal and circumferential strain is known to be abnormal in myocarditis. CMR strain is a useful additional tool that can identify subclinical myocardial involvement and may help with longitudinal follow-up. Right ventricular strain derived by CMR in children has not been studied. We sought to evaluate CMR derived biventricular strain in children with acute myocarditis.

METHODS

Children with acute myocarditis who underwent CMR between 2016-2022 at our center were reviewed, this group included subjects with COVID-19 myocarditis. Children with no evidence of myocarditis served as controls Those with congenital heart disease and technically limited images for CMR strain analysis were excluded from final analysis. Biventricular longitudinal, circumferential, and radial peak systolic strains were derived using circle cvi42®. Data between cases and controls were compared using an independent sample t-test. One-way ANOVA with post hoc analysis was used to compare COVID-19, non-COVID myocarditis and controls.

RESULTS

38 myocarditis and 14 controls met inclusion criteria (mean age 14.4 ± 3 years). All CMR derived peak strain values except for RV longitudinal strain were abnormal in myocarditis group. One-way ANOVA revealed that there was a statistically significant difference with abnormal RV and LV strain in COVID-19 myocarditis when compared to non-COVID-19 myocarditis and controls.

CONCLUSION

CMR derived right and left ventricular peak systolic strain using traditionally acquired cine images were abnormal in children with acute myocarditis. All strain measurements were significantly abnormal in children with COVID-19 even when compared to non-COVID myocarditis.

Imaging Acute and Chronic Cardiac Complications of COVID-19 and after COVID-19 Vaccination

COVID-19 is associated with acute and longer-term cardiovascular manifestations including myocardial injury, myopericarditis, stress-induced cardiomyopathy, myocardial infarction, and thromboembolic disease. Although the morbidity and mortality related to acute COVID-19 have decreased substantially, there is growing concern about the longer-term cardiovascular effects of the disease and postacute sequelae. Myocarditis has also been reported after messenger ribonucleic acid (mRNA)-based COVID-19 vaccination, with the highest risk among adolescent boys and young adult men. Noninvasive imaging including cardiac MRI has a key role in identifying the presence of cardiovascular disease, evaluating for potential mechanisms of injury, stratifying risk of future adverse cardiovascular events, and potentially guiding treatment in patients with suspected cardiovascular injury after COVID-19 and vaccination. Patterns of injury identified at cardiac MRI after COVID-19 include myocarditis and pericarditis, myocardial ischemia, and infarction. Myocardial edema and late gadolinium enhancement have been described months after the initial infection in a minority of patients with persistent cardiac symptoms after COVID-19. In patients with myocarditis after receiving a COVID-19 vaccination, the most common pattern of late gadolinium enhancement is subepicardial at the basal inferolateral wall, and patients tend to have milder imaging abnormalities compared with those from other causes of myocarditis. This article describes the role of multimodality cardiac imaging and imaging findings in patients with acute and longer-term cardiovascular manifestations of COVID-19 and in patients with myocarditis after receiving an mRNA-based COVID-19 vaccination. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Myocardial Tissue Characterization in Cardiac Magnetic Resonance Studies of Patients Recovering From COVID-19: A Meta-Analysis

Background Meta-analysis can identify biological factors that moderate cardiac magnetic resonance myocardial tissue markers such as native T1 (longitudinal magnetization relaxation time constant) and T2 (transverse magnetization relaxation time constant) in cohorts recovering from COVID-19 infection. Methods and Results Cardiac magnetic resonance studies of patients with COVID-19 using myocardial T1, T2 mapping, extracellular volume, and late gadolinium enhancement were identified by database searches. Pooled effect sizes and interstudy heterogeneity (I2) were estimated with random effects models. Moderators of interstudy heterogeneity were analyzed by meta-regression of the percent difference of native T1 and T2 between COVID-19 and control groups (%ΔT1 [percent difference of the study-level means of myocardial T1 in patients with COVID-19 and controls] and %ΔT2 [percent difference of the study-level means of myocardial T2 in patients with COVID-19 and controls]), extracellular volume, and the proportion of late gadolinium enhancement. Interstudy heterogeneities of %ΔT1 (I2=76%) and %ΔT2 (I2=88%) were significantly lower than for native T1 and T2, respectively, independent of field strength, with pooled effect sizes of %ΔT1=1.24% (95% CI, 0.54%-1.9%) and %ΔT2=3.77% (95% CI, 1.79%-5.79%). %ΔT1 was lower for studies in children (median age: 12.7 years) and athletes (median age: 21 years), compared with older adults (median age: 48 years). Duration of recovery from COVID-19, cardiac troponins, C-reactive protein, and age were significant moderators for %ΔT1 and/or %ΔT2. Extracellular volume, adjusted by age, was moderated by recovery duration. Age, diabetes, and hypertension were significant moderators of the proportion of late gadolinium enhancement in adults. Conclusions T1 and T2 are dynamic markers of cardiac involvement in COVID-19 that reflect the regression of cardiomyocyte injury and myocardial inflammation during recovery. Late gadolinium enhancement and to a lesser extent extracellular volume, are more static biomarkers moderated by preexisting risk factors linked to adverse myocardial tissue remodeling.

Utilization of Cardiovascular Magnetic Resonance Imaging for Resumption of Athletic Activities Following COVID-19 Infection: An Expert Consensus Document on Behalf of the American Heart Association Council on Cardiovascular Radiology and Intervention Leadership and Endorsed by the Society for Cardiovascular Magnetic Resonance

The global pandemic of COVID-19 caused by infection with SARS-CoV-2 is now entering its fourth year with little evidence of abatement. As of December 2022, the World Health Organization Coronavirus (COVID-19) Dashboard reported 643 million cumulative confirmed cases of COVID-19 worldwide and 98 million in the United States alone as the country with the highest number of cases. Although pneumonia with lung injury has been the manifestation of COVID-19 principally responsible for morbidity and mortality, myocardial inflammation and systolic dysfunction though uncommon are well-recognized features that also associate with adverse prognosis. Given the broad swath of the population infected with COVID-19, the large number of affected professional, collegiate, and amateur athletes raises concern regarding the safe resumption of athletic activity (return to play) following resolution of infection. A variety of different testing combinations that leverage ECG, echocardiography, circulating cardiac biomarkers, and cardiovascular magnetic resonance imaging have been proposed and implemented to mitigate risk. Cardiovascular magnetic resonance in particular affords high sensitivity for myocarditis but has been employed and interpreted nonuniformly in the context of COVID-19 thereby raising uncertainty as to the generalizability and clinical relevance of findings with respect to return to play. This consensus document synthesizes available evidence to contextualize the appropriate utilization of cardiovascular magnetic resonance in the return to play assessment of athletes with prior COVID-19 infection to facilitate informed, evidence-based decisions, while identifying knowledge gaps that merit further investigation.

Cardiac Involvement in Children Affected by COVID-19: Clinical Features and Diagnosis

COVID-19 (Coronavirus disease 2019) in children is usually mild. However, multiple organ disorders associated with SARS-CoV-2 (severe acute respiratory syndrome-related coronavirus 2) have been detected with poor respiratory symptoms. Cardiac changes are noted in 17% to 75% of cases, which are associated with diagnostic difficulties in high-risk groups for the development of complications that are associated with myocardial damage by the SARS-CoV-2 virus. The objective of this review is to identify the most significant symptoms of cardiac involvement affected by COVID-19, which require in-depth examination. The authors analyzed publications from December 2019 to the October 2022, which were published in accessible local and international databases. According to the analysis data, the main sign of myocardial involvement was increasing as cardiomarkers in the patient's blood, in particular troponin I or troponin T. Many authors noted that the increased level of CRP (C-reactive protein) and NT-proBNP, which are accompanied by changes in the ECG (electrocardiogram) and EchoCG (echocardiography), as a rule, were nonspecific. However, the identified cardiac functional dysfunctions affected by SARS-CoV-2, required an cardiac MRI. The lack of timely diagnosis of myocardial involvements, especially in children at high risk for the development of complications associated with SARS-CoV-2 myocardial injury, can lead to death. The direct damage of the structural elements of myocardial blood vessels in patients with severe hypoxic changes resulted from respiratory failure caused by SARS-CoV-2 lung damage, with the development of severe acute diffuse alveolar damage and cell-mediated immune response and myocardial involvement affected by SARS-CoV-2 damage. In this article, the authors introduce a clinical case of a child who dead from inflammatory myocardities with COVID-19 in a background of congenital heart disease and T-cell immunodeficiency.

Utilization of cardiovascular magnetic resonance (CMR) imaging for resumption of athletic activities following COVID-19 infection: an expert consensus document on behalf of the American Heart Association Council on Cardiovascular Radiology and Intervention (CVRI) Leadership and endorsed by the Society for Cardiovascular Magnetic Resonance (SCMR)

The global pandemic of coronavirus disease 2019 (COVID-19) caused by infection with severe acute respiratory suyndrome coronavirus 2 (SARS-CoV-2) is now entering its 4th year with little evidence of abatement. As of December 2022, the World Health Organization Coronavirus (COVID-19) Dashboard reported 643 million cumulative confirmed cases of COVID-19 worldwide and 98 million in the United States alone as the country with the highest number of cases. While pneumonia with lung injury has been the manifestation of COVID-19 principally responsible for morbidity and mortality, myocardial inflammation and systolic dysfunction though uncommon are well-recognized features that also associate with adverse prognosis. Given the broad swath of the population infected with COVID-19, the large number of affected professional, collegiate, and amateur athletes raises concern regarding the safe resumption of athletic activity (return to play, RTP) following resolution of infection. A variety of different testing combinations that leverage the electrocardiogram, echocardiography, circulating cardiac biomarkers, and cardiovascular magnetic resonance (CMR) imaging have been proposed and implemented to mitigate risk. CMR in particular affords high sensitivity for myocarditis but has been employed and interpreted non-uniformly in the context of COVID-19 thereby raising uncertainty as to the generalizability and clinical relevance of findings with respect to RTP. This consensus document synthesizes available evidence to contextualize the appropriate utilization of CMR in the RTP assessment of athletes with prior COVID-19 infection to facilitate informed, evidence-based decisions, while identifying knowledge gaps that merit further investigation.

Cardiac magnetic resonance follow-up of COVID-19 vaccine associated acute myocarditis

BACKGROUND

Mass COVID-19 vaccination campaigns have helped impede the COVID-19 pandemic. In rare cases, some vaccines have led to vaccine associated myocarditis in a specific subset of the population, usually young males. Cardiac magnetic resonance (CMR) can reliably diagnose vaccine associated myocarditis, but follow-up data of CMR proven acute myocarditis is scarce.

MATERIALS AND METHODS

Nine patients with acute vaccine associated myocarditis underwent baseline and follow-up CMR examinations and were compared to baseline parameters at initial presentation and to a group of 20 healthy controls. CMR protocol included functional assessment, T1 and T2 mapping, T2 signal intensity ratio, strain feature tracking, and late gadolinium enhancement (LGE).

RESULTS

Myocarditis patients (n = 9, aged 24 ± 6 years, 8 males) underwent CMR follow-up after an average of 5.8 ± 4.3 months. All patients showed a complete resolution of visual myocardial edema while also demonstrating a reduction in overall LGE extent from baseline to follow-up (4.2 ± 2.1 vs. 0.9 ± 0.8%, p < 0.001), although visual LGE was still noted in all patients. Left ventricular ejection fraction was normal at baseline and at follow-up (58 ± 6 vs. 62 ± 4%, p = 0.10) as well as compared to a healthy control group (60 ± 4%, p = 0.24). T1 (1024 ± 77 vs. 971 ± 34 ms, p = 0.05) and T2 relaxations times (57 ± 6 vs. 51 ± 3 ms, p = 0.03) normalized at follow-up. Most patients reported a resolution of clinical symptoms, while two (22%) reported new onset of exertional dyspnea.

CONCLUSION

Patients with COVID-19 vaccine associated acute myocarditis showed a complete, uncomplicated resolution of myocardial inflammation on follow-up CMR, which was associated with a near complete resolution of symptoms. Minor, residual myocardial scarring was present on follow-up LGE imaging. The long-term implications of the remaining myocardial scar-tissue after vaccine associated myocarditis remain unknown warranting further studies.

Parametric Mapping Cardiac Magnetic Resonance Imaging for the Diagnosis of Myocarditis in Children in the Era of COVID-19 and MIS-C

Myocarditis comprises many clinical presentations ranging from asymptomatic to sudden cardiac death. The history, physical examination, cardiac biomarkers, inflammatory markers, and electrocardiogram are usually helpful in the initial assessment of suspected acute myocarditis. Echocardiography is the primary tool to detect ventricular wall motion abnormalities, pericardial effusion, valvular regurgitation, and impaired function. The advancement of cardiac magnetic resonance (CMR) imaging has been helpful in clinical practice for diagnosing myocarditis. A recent Scientific Statement by the American Heart Association suggested CMR as a confirmatory test to diagnose acute myocarditis in children. However, standard CMR parametric mapping parameters for diagnosing myocarditis are unavailable in pediatric patients for consistency and reliability in the interpretation. The present review highlights the unmet clinical needs for standard CMR parametric criteria for diagnosing acute and chronic myocarditis in children and differentiating dilated chronic myocarditis phenotype from idiopathic dilated cardiomyopathy. Of particular relevance to today’s practice, we also assess the potential and limitations of CMR to diagnose acute myocarditis in children exposed to severe acute respiratory syndrome coronavirus-2 infections. The latter section will discuss the multi-inflammatory syndrome in children (MIS-C) and mRNA coronavirus disease 19 vaccine-associated myocarditis.

Frontiers of COVID-19-related myocarditis as assessed by cardiovascular magnetic resonance

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In some patients, COVID-19 is complicated with myocarditis. Early detection of myocardial injury and timely intervention can significantly improve the clinical outcomes of COVID-19 patients. Although endomyocardial biopsy (EMB) is currently recognized as the ‘gold standard’ for the diagnosis of myocarditis, there are large sampling errors, many complications and a lack of unified diagnostic criteria. In addition, the clinical methods of treating acute and chronic COVID-19-related myocarditis are different. Cardiac magnetic resonance (CMR) can evaluate the morphology of the heart, left and right ventricular functions, myocardial perfusion, capillary leakage and myocardial interstitial fibrosis to provide a noninvasive and radiation-free diagnostic basis for the clinical detection, efficacy and risk assessment, and follow-up observation of COVID-19-related myocarditis. However, for the diagnosis of COVID-19-related myocarditis, the Lake Louise Consensus Criteria may not be fully applicable. COVID-19-related myocarditis is different from myocarditis related to other viral infections in terms of signal intensity and lesion location as assessed by CMR, which is used to visualize myocardial damage, locate lesions and quantify pathological changes based on various sequences. Therefore, the standardized application of CMR to timely and accurately evaluate heart injury in COVID-19-related myocarditis and develop rational treatment strategies could be quite effective in improving the prognosis of patients and preventing potential late-onset effects in convalescent patients with COVID-19.

Myocardial oedema: pathophysiological basis and implications for the failing heart

Myocardial fluid homeostasis relies on a complex interplay between microvascular filtration, interstitial hydration, cardiomyocyte water uptake and lymphatic removal. Dysregulation of one or more of these mechanisms may result in myocardial oedema. Interstitial and intracellular fluid accumulation disrupts myocardial architecture, intercellular communication, and metabolic pathways, decreasing contractility and increasing myocardial stiffness. The widespread use of cardiac magnetic resonance enabled the identification of myocardial oedema as a clinically relevant imaging finding with prognostic implications in several types of heart failure. Furthermore, growing experimental evidence has contributed to a better understanding of the physical and molecular interactions in the microvascular barrier, myocardial interstitium and lymphatics and how they might be disrupted in heart failure. In this review, we summarize current knowledge on the factors controlling myocardial water balance in the healthy and failing heart and pinpoint the new potential therapeutic avenues.

Cardiac MRI Assessment of Nonischemic Myocardial Inflammation: State of the Art Review and Update on Myocarditis Associated with COVID-19 Vaccination

Myocarditis is a nonischemic inflammatory disease of the myocardium that can be triggered by a multitude of events, including viral infection and toxins. Recently, there has been heightened interest in myocarditis given its association with COVID-19 vaccination. Timely identification of myocarditis can affect patient management and prognosis. Therefore, it is crucial for radiologists and cardiac imagers to understand the role of cardiac imaging to establish a diagnosis and inform treatment decisions. Cardiac MRI is the most important noninvasive imaging modality for evaluation of myocarditis, with typical findings of focal or diffuse myocardial edema and myocardial damage, including presence of late gadolinium enhancement. There are currently limited data available to indicate that the pattern of myocardial injury following COVID-19 vaccination is similar to other causes of myocarditis, although the severity of disease may be relatively mild. A description of the role of imaging and typical imaging features will be reviewed here, with a focus on emerging data in the setting of myocarditis after COVID-19 vaccination. Keywords: MRI, Heart, Inflammation © RSNA, 2021.

Role of cardiac magnetic resonance imaging in the diagnosis and management of COVID-19 related myocarditis: Clinical and imaging considerations

There is a growing evidence of cardiovascular complications in coronavirus disease 2019 (COVID-19) patients. As evidence accumulated of COVID-19 mediated inflammatory effects on the myocardium, substantial attention has been directed towards cardiovascular imaging modalities that facilitate this diagnosis. Cardiac magnetic resonance imaging (CMRI) is the gold standard for the detection of structural and functional myocardial alterations and its role in identifying patients with COVID-19 mediated cardiac injury is growing. Despite its utility in the diagnosis of myocardial injury in this population, CMRI’s impact on patient management is still evolving. This review provides a framework for the use of CMRI in diagnosis and management of COVID-19 patients from the perspective of a cardiologist. We review the role of CMRI in the management of both the acutely and remotely COVID-19 infected patient. We discuss patient selection for this imaging modality; T1, T2, and late gadolinium enhancement imaging techniques; and previously described CMRI findings in other cardiomyopathies with potential implications in COVID-19 recovered patients.

Laboratory and Imaging Evaluation of Cardiac Involvement in Patients with Post-Acute COVID-19

Background

In the post-acute COVID-19 syndrome, many patients suffer from palpitations, effort-associated fatigue, and even sudden death. The mechanism of heart involvement in this syndrome is uncertain. The main purpose of the study was to identify possible cardiac involvement causes in patients with post-acute COVID-19 by using biomarkers such as NT-proBNP and nitric oxide (NO) and cardiac imaging modalities.

Methods

In this cross-sectional study, a total of 105 participants were included according to the existence of symptoms, and 40 of these participants were asymptomatic patients. The ages of the participants ranged from 20 to 50 years. All patients were healthy before COVID-19. The symptoms were defined as palpitations and/or fatigue association with exercise in post-acute COVID-19 term. The comparison of the two groups was made by using biochemical parameters (NT-proBNP, Troponin I, NO) and imaging techniques (echocardiography, cardiovascular magnetic resonance (CMR) and cardiac positron emission tomography (PET)).

Results

The symptomatic patients had higher NT-proBNP levels compared with asymptomatic patients (132.30±35.15; 76.86±16.79, respectively; p < 0.001). Interestingly, the symptomatic patients had lower NO levels than asymptomatic patients (9.20±3.08; 16.15±6.02, respectively; p < 0.001). Echocardiography and CMR were normal. However, we found regional increased 18F-FDG uptake on cardiac PET to be compatible with myocardial fatigue.

Conclusion

We found elevated NT-proNBP levels, low serum NO levels, and increased 18F-FDG uptake on cardiac PET in post-acute COVID syndrome. Cardiac PET could replace or be added to CMR for detecting subtle subacute/chronic myocarditis. The follow-up of patients with post-acute COVID-19 could target the possibility of risk of heart failure.

COVID-19 Myocarditis: Rationale for Early Diagnosis and Intervention

Myocarditis is a common cardiovascular manifestation seen in patients diagnosed with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. However, because of the similarity of presentation with other cardiopulmonary pathologies, identification of coronavirus disease 2019 (COVID-19) related myocarditis can be challenging. Transthoracic echocardiography is a key component in initial diagnosis. COVID-19 related myocarditis is increasingly identified as an underlying problem in COVID-19 patients with low ejection fraction. Early recognition is critical with a low threshold for screening echocardiogram. Utilization of cardiac MRI (CMRI) can be helpful in recognition of early manifestations of COVID-19 myocarditis, with the added benefit of avoidance of invasive testing such as endomyocardial biopsy (EMB). Once diagnosis is established, disease-specific treatment can lead to rapid recovery of ventricular systolic function. We present a case series including two similar cases of COVID-19 myocarditis in which we utilized echocardiography as an early diagnostic tool and prompt treatment led to better prognosis. 

Cardiac MRI in Patients with Prolonged Cardiorespiratory Symptoms after Mild to Moderate COVID-19 Infection

Background

Myocardial injury and inflammation at cardiac MRI in patients with COVID-19 have been described in recent publications. Concurrently, a chronic COVID-19 syndrome (CCS) after SARS-CoV-2 infection has been observed and manifests with symptoms such as fatigue and exertional dyspnea.

Purpose

To explore the relationship between CCS and myocardial injury and inflammation as an underlying cause of the persistent complaints in previously healthy individuals.

Materials and Methods

In this prospective study from January 2021 to April 2021, study participants without known cardiac or pulmonary diseases prior to SARS-CoV-2 infection who had persistent CCS symptoms such as fatigue or exertional dyspnea after convalescence and healthy control participants underwent cardiac MRI. The cardiac MRI protocol included evaluating the T1 and T2 relaxation times, extracellular volume, T2 signal intensity ratio, and late gadolinium enhancement (LGE). Student t tests, Mann-Whitney U tests, and χ² tests were used for statistical analysis.

Results

Forty-one participants with CCS (mean age, 39 years ± 13 [standard deviation]; 18 men) and 42 control participants (mean age, 39 years ± 16; 26 men) were evaluated. The median time between the initial incidence of mild to moderate COVID-19 not requiring hospitalization and undergoing cardiac MRI was 103 days (interquartile range, 88–158 days). Troponin T levels were normal. Parameters indicating myocardial inflammation and edema were comparable between participants with CCS and control participants (T1 relaxation times: 978 msec ± 23 vs 971 msec ± 25 [P = .17]; T2 relaxation times: 53 msec ± 2 vs 52 msec ± 2 [P = .47]; T2 signal intensity ratios: 1.6 ± 0.2 vs 1.6 ± 0.3 [P = .10]). Visible myocardial edema was present in none of the participants. Three of 41 (7%) participants with CCS demonstrated nonischemic LGE, whereas no participants in the control group demonstrated nonischemic LGE (0 of 42 [0%]; P = .07). None of the participants fulfilled the 2018 Lake Louise criteria for the diagnosis of myocarditis.

Conclusion

Individuals with chronic COVID-19 syndrome who did not undergo hospitalization for COVID-19 did not demonstrate signs of active myocardial injury or inflammation at cardiac MRI.

© RSNA, 2021

Online supplemental material is available for this article.

See also the editorial by Lima and Bluemke in this issue.