REN and chronic kidney disease: Cox proportional regression was performed to investigate the factors associated with differences in mortality rates between the groups; the factors investigated were age; sex; past history of hypertension, diabetes, chronic kidney disease, stroke, and/or previous percutaneous coronary intervention; history of undertaking aspirin, clopidogrel, statin, renin-angiotensin system blocker, and/or calcium channel blocker therapy; ejection fraction after revascularisation; culprit coronary lesion (left main coronary artery or LAD); CPR duration; ECMO duration; and the need for bailout ECMO.