Cardiac inflammation after mild COVID-19 in previously healthy people

By Suchandrima BhowmikReviewed by Danielle Ellis, B.Sc.Sep 27 2022

Research has recognized several post-acute-COVID-19 outcomes, such as lingering cardiac symptoms involving tachycardia, exercise intolerance, and chest pain. Patients with severe disease, pre-existing conditions, and cardiac injury commonly show cardiac symptoms. In some instances, people with mild COVID-19 showed rare signs of cardiac damage, wherein the cardiac symptoms were profound. Moreover, subtle non-ischemic cardiac inflammatory changes have been observed previously in populations comprising young athletic people following COVID-19 infections. However, whether these early signs are related to cardiac symptoms or persist with time is unclear.

A new study published in the journal Nature Medicine aimed to analyze the association of lingering cardiac symptoms with mild COVID-19.

Research Briefing: Lingering cardiac involvement in previously well people after mild COVID-19. Image Credit: Kateryna Kon / Shutterstock

About the study

The study involved people with no heart disease and who experienced mild, acute COVID-19 illness. They underwent serial blood tests and had to answer standardized symptom questionnaires. The baseline assessments were carried out after four weeks of COVID-19 diagnosis, while follow-ups were carried out for at least four months. Detection of subtle changes in strain and function was done using sensitive MRI measurements.

Tissue mapping was used to assess diffuse myocardial infarction where T1 mapping measured abnormal myocardium and T2 mapping measured inflammatory myocardial edema. The presence of extracellular space and pericardial fluid within the pericardium and myocardium was also evaluated.

Study findings

The results reported that 73% of the participants showed cardiac symptoms at baseline, while 57% continued to experience the symptoms at follow-up. Signs of inflammatory cardiac involvement were observed that persevered for many months post-acute COVID-19 and were more prominent in participants with symptoms than those without symptoms. However, these changes were not observed to be associated with increased biomarkers or structural heart disease. At follow-up, T2 was reported to be higher for participants with persistent cardiac symptoms. Moreover, abnormal myocardial measurements and female sex were indicative of persistent symptoms at follow-up.

Therefore, the current study confirms cardiac symptoms as an important risk factor for post-acute COVID-19 in people with mild COVID-19. These symptoms can be due to cardiac inflammation, leading to poor prognosis and heart failure. However, further research must be done to accurately predict the cause and impact of such symptoms and interventions for preventing them.

Limitations

The current study has certain limitations. First, the findings of this study have limited transferability due to a lack of methodological variations and standardization. Second, the study's results cannot be extrapolated to the general population since the study involved a small population who recently recovered from COVID-19.