AUTHOR=Shanmuganathan Mayooran , Kotronias Rafail A. , Burrage Matthew K. , Ng Yujun , Banerjee Abhirup , Xie Cheng , Fletcher Alison , Manley Peter , Borlotti Alessandra , Emfietzoglou Maria , Mentzer Alexander J. , Marin Federico , Raman Betty ,  Oxford Acute Myocardial Infarction (OxAMI) investigators , Tunnicliffe Elizabeth M. , Neubauer Stefan , Piechnik Stefan K. , Channon Keith M. , Ferreira Vanessa M. 

TITLE=Acute changes in myocardial tissue characteristics during hospitalization in patients with COVID-19

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2023.1097974

DOI=10.3389/fcvm.2023.1097974

ISSN=2297-055X

ABSTRACT=Background: Patients with a history of COVID-19 infection are reported to have cardiac abnormalities on cardiovascular magnetic resonance (CMR) during convalescence. However, it is unclear whether these abnormalities were present during the acute COVID-19 illness and how they may evolve over time. 
Methods: We prospectively recruited unvaccinated patients hospitalized with acute COVID-19 (n=23), and compared them with matched outpatient controls without COVID-19 (n=19) between May 2020 and May 2021. We performed in-hospital CMR at a median of 3 days (IQR 1-7 days) after admission, and assessed cardiac function, edema and necrosis/fibrosis, using left and right ventricular ejection fraction (LVEF, RVEF), T1-mapping, T2 signal intensity ratio (T2SI), late gadolinium enhancement (LGE) and extracellular volume (ECV). Acute COVID-19 patients were invited for follow-up CMR and blood tests at 6 months.
Results: The two cohorts were well matched in baseline clinical characteristics. Both had normal LVEF (62±7 vs 65±6%), RVEF (60±6 vs 58±6%), ECV (31±3 vs 31±4%), and similar frequency of LGE abnormalities (16 vs 14%) (all p>0.05). However, measures of acute myocardial edema (T1 and T2SI) were significantly higher in patients with acute COVID-19 when compared to controls (T1=1217±41ms vs 1183±22ms; p=0.002; T2SI=1.48±0.36 vs 1.13±0.09; p<0.001). All COVID-19 patients who returned for follow up (n=12) at 6 months had normal biventricular function, T1 and T2SI. 
Conclusion: Unvaccinated patients hospitalized for acute COVID-19 demonstrated CMR imaging evidence of acute myocardial edema, which normalized at 6-months, while biventricular function and scar burden were similar when compared to controls. Acute COVID-19 appears to induce acute myocardial edema in some patients, which resolves in convalescence, without significant impact on biventricular structure and function in the acute and short-term. Further studies with larger numbers are needed to confirm these findings.