The UK Biobank is a versatile scientific resource, in which questionnaire data, physical measurements and biological samples were collected from over 500,000 individuals aged 40–69 between 2006 and 2010 registered with the UK National Health Service; the study protocol has been described in detail previously . Additionally, the UK Biobank imaging enhancement study is ongoing with the aim of performing, in a single visit, brain, heart, whole body, carotid artery, bone and joint imaging in 100,000 of the original 500,000 participants. Cardiovascular magnetic resonance imaging (CMR) was selected as the modality of choice for heart imaging. The study population presented here consists of 1604 individuals, a subset of the 5,065 individuals who underwent CMR examination as part of the pilot phase (April 2014 –August 2015) of the UK Biobank imaging enhancement. All participants provided written consent; UK Biobank’s scientific protocol and operational procedures were reviewed and approved by the North West Multi-centre Research Ethics Committee in the UK . The research presented here was conducted under access application 2964 and was approved by the UK Biobank access committee.