 Heart failure HF is a major medical problem in the western world. Heart failure is associated with a substantial morbidity and mortality and contributes to a significant extent to economic loss for healthcare systems. An increased prevalence of HF is expected as survival is increasing after an ischaemic event due to primary percutaneous coronary intervention PCI and due to demographic changes ageing population. At this moment, no contemporary data of large scale electronic health records cohorts have been reported regarding the incidence of HF following myocardial infarction MI. The aim of this research is to investigate the incidence of HF following MI across different time periods and search for predictors of HF following MI to identify high-risk patients. Using CALIBER Cardiovascular disease research using linked bespoke studies and electronic records data, patients with HF following MI will be identified and the incidence of HF after MI will be described. Prognostic factors associated with the occurrence of HF in patients having experienced a MI will be studied. This is important for future observational research, clinical trials, measuring health outcomes and guideline development. 