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.