1 St George's Vascular Institute, St George's University Hospitals NHS Foundation Trust, London, UK; St George's University of London, London, UK. Electronic address: ian.loftus@stgeorges.nhs.uk.
2 Keele University School of Medicine, University Hospitals of North Midlands NHS Trust, Stoke-on-Trent, UK. Electronic address: https://twitter.com/adpherwani.
3 St George's Vascular Institute, St George's University Hospitals NHS Foundation Trust, London, UK; St George's University of London, London, UK. Electronic address: https://twitter.com/barnabyfarq.