Acknowledgements
This work was supported by grants from the Natural Science Foundation of China (Grant 81702615/H1622).
Conflict of interest The authors have no conflict of interest to disclose.
Ethical Statement All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Permission was gained from the local ethics committee of Sun Yat-sen Memorial Hospital for this retrospective analysis. For this type of study, formal consent was not required. All data were recorded and analysed anonymously.