Cardiorespiratory Optimisation By Arteriovenous fistula Ligation after renal Transplantation (COBALT): study protocol for a multicentre randomised interventional feasibility trial oleh Madalina Garbi, Leila Rooshenas, Jennifer Banks, James Hunter, Dominic Summers, Matthew Slater, Matthew Bartlett, Anna Sidders, Cara Hudson, Simon Knight, Reza Motallebzadeh, Gavin Pettigrew, Veena Surendrakumar, Andrew Norton, Karl Sylvester, Patrick Mark, Emma Aitken, Aimen Amer, Kirsten Rennie