METHODS

Study population
We considered patients who had orthotopic heart transplants in our centre from 1985 to 2020. Heart transplant recipients affected with COVID-19 were included in the present investigation. We collected data related to risk factors, last follow-up characteristics, COVID-19 onset presentation, in-hospital course of disease and results from blood tests.

Ethical statement
The use of data for scientific and research purposes is mentioned in the current informed consent in use at the Cardiac Surgery Unit of Padova. We guarantee to respect patient anonymity and professional secrecy, and we use the collected data and the statistical analyses of this study solely for the scientific uses granted in accordance with the law in force (General Data Protection Regulation).

Statistical analyses
Continuous variables are expressed as median and interquartile range (IQR); categorical variables are presented as count and frequency. All statistical analyses were performed using SPSS software version 20 (IBM SPSS Statistics, IBM Corp., Armonk, NY, USA).