Funding for this research was provided by:
British Heart Foundation (FS/15/34/31656)
Received: 27 July 2020
Accepted: 26 October 2021
First Online: 22 November 2021
: Written consent was obtained from all participants. Ethical approval was obtained from the ethical review committees of the Faculty of Medicine, University of Colombo (EC-18-111) and the Oxford Tropical Research Ethics Committee (OxTREC), University of Oxford (561–18).
: Not applicable.
: The authors declare that they have no competing interests.