For in-hospital data collection, CCSR established 11 modules (patient basic information, preoperative risks, cardiovascular presentation, cardiac examination, general information on operation, CABG, valve surgery, other surgeries, post-operative complications, pre-operative medication and medical order at discharge), 416 items, among which 157 items are core dataset, 259 are extended dataset. The core dataset is a mandatory set of variables believed to be necessary for accurate representation of clinical practice, risk model development, and analysis. The extended dataset includes less critical but still important fields that are strongly encouraged to be collected but are not mandatory for submitting. The creation of custom fields is permissible so that sites can collect specific information that is desired by themselves.