Data describe supplementary tables and figures related to the research article; Effect of early, individualised and intensified follow-up after open heart valve surgery on unplanned cardiac hospital readmissions and all-cause mortality [1]. Data on patients undergoing open heart valve surgery were presented in 308 patients in a prospective cohort and compared with 980 patients in a historical cohort. Included figures show inclusion and exclusion of patients (flowchart)and the specific elements of the intervention. Tables show causes of readmission and sensitivity analyses of differences among patients in the prospective intervention group compared with patients in the historical control group. Further results, interpretation and discussion of the included data can be found in the main research paper.