Funding for this research was provided by:
Chest Heart and Stroke Scotland (R15/A164)
British Heart Foundation (PG/17/63/33198)
Received: 21 November 2017
Accepted: 2 December 2018
First Online: 29 December 2018
Ethics approval and consent to participate
: A favourable ethical opinion was obtained from South East Scotland Research Ethics Committee 02 (REC reference: 16/SS/0074) on 5 May 2016 for the Edinburgh site and from HRA on 29 December 2016 for all other sites. Written consent was obtained from all participants.
: Not applicable.
: The authors declare that they have no competing interests.
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