Received: 16 July 2020
Accepted: 8 November 2020
First Online: 6 March 2021
Ethics approval and consent to participate
: This retrospective database analysis did not involve the collection, use, or transmittal of individual identifiable data. As such, Institutional Review Board (IRB) approval to conduct this study was not required and considered exempt according to 45CFR46.101(b)(4): Existing Data & Specimens—No Identifiers. Both the data set itself and the security of the offices where the data are housed meet the requirements of the Health Insurance Portability and Accountability Act (HIPAA) of 1996. Administrative permissions were required to access the raw data from Sichuan Provincial People's Hospital.With the permission of Sichuan Provincial People's Hospital and the department of Cardiovascular Medicine, we were allowed to access the raw data of Sichuan Provincial People's Hospital.
: Not applicable.
: The authors declare that they have no competing interests.