Footnotes

• Twitter @Franke_Jen

• Contributors All authors (LZ, JF, MRC) have made substantial contributions to the conception and design of the work. They have drafted and revised it critically for important intellectual content and have provided final approval of the version to be published. Further, all authors have agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Disclaimer The content hereof is the sole responsibility of the authors and does not necessarily represent the official views of the SAMRC.

• Competing interests MRC is employed by AstraZeneca as Clinical Vice President, Cardiovascular and Heart Failure, late CVRM, Biopharmaceuticals Research and Development. JF is employed by Philips as Zone Business Leader Image Guided Therapy in Germany, Austria and Switzerland. LZ is funded by the South African Medical Research Council (SAMRC) through its Division of Research Capacity Development under the Mid-Career Scientist Programme from funding received from the South African National Treasury. LZ also receives support from the National Research Foundation of South Africa (NRFSA), as well as the UK Medical Research Council (MRC) and the UK Department for International Development (DFID) under the MRC/DFID Concordat agreement, via the African Research Leader Award (MR/S005242/1).

• Provenance and peer review Commissioned; internally peer reviewed.