BackgroundCardiovascular magnetic resonance (CMR) imaging shows promise in estimating pulmonary capillary wedge pressure (PCWP) non‐invasively. At the population level, the prognostic role of CMR‐modelled PCWP remains unknown. Furthermore, the relationship between CMR‐modelled PCWP and established risk factors for cardiovascular disease has not been well characterized.ObjectiveThe main aim of this study was to investigate the prognostic value of CMR‐modelled PCWP at the population level.MethodsEmploying data from the imaging substudy of the UK Biobank, a very large prospective population‐based cohort study, CMR‐modelled PCWP was calculated using a model incorporating left atrial volume, left ventricular mass and sex. Logistic regression explored the relationships between typical cardiovascular risk factors and raised CMR‐modelled PCWP (≥15 mmHg). Cox regression was used to examine the impact of typical risk factors and CMR‐modelled PCWP on heart failure (HF) and major adverse cardiovascular events (MACE).ResultsData from 39 163 participants were included in the study. Median age of all participants was 64 years (inter‐quartile range: 58 to 70), and 47% were males. Clinical characteristics independently associated with raised CMR‐modelled PCWP included hypertension [odds ratio (OR) 1.57, 95% confidence interval (CI) 1.44–1.70, P < 0.001], body mass index (BMI) [OR 1.57, 95% CI 1.52–1.62, per standard deviation (SD) increment, P < 0.001], male sex (OR 1.37, 95% CI 1.26–1.47, P < 0.001), age (OR 1.33, 95% CI 1.27–1.41, per decade increment, P < 0.001) and regular alcohol consumption (OR 1.10, 95% CI 1.02–1.19, P = 0.012). After adjusting for potential confounders, CMR‐modelled PCWP was independently associated with incident HF [hazard ratio (HR) 2.91, 95% CI 2.07–4.07, P < 0.001] and MACE (HR 1.48, 95% CI 1.16–1.89, P = 0.002).ConclusionsRaised CMR‐modelled PCWP is an independent risk factor for incident HF and MACE. CMR‐modelled PCWP should be incorporated into routine CMR reports to guide HF diagnosis and further management.