HeAlth-data Register sTudies of Risk and Outcomes in Cardiac Surgery

The purpose of this research project is to study risks and outcomes in patients who underwent cardiac surgery. We aim to establish a fundament for the conduct of nationwide population-based studies by linking patient-level data from the Swedish Heart Surgery Register (SWEDEHEART), the National Patient Register, the Cause of Death Register, the National Diabetes Register, the Swedish Renal Registry, the Prescribed Drug Register, and the 2nd version of the Swedish-Danish Scandinavian Donations and Transfusions database. Cross-linking patient-level data is possible through the Personal Identity Number assigned to every individual who has resided in Sweden on a permanent basis. The Swedish Personal Identity Number is the unique identifier in all national registers. Specifically, we aim: 1. To assess the importance of chronic kidney disease for prognosis after CABG. 2. To assess the consequences of acute kidney injury following CABG. 3. To analyze the prognosis in patients with depression prior to CABG. 4. To study risks and benefits of blood transfusions in cardiac surgery. 5. To study the risks associated with diabetes mellitus in cardiac surgery with special reference to type of diabetes (type 1 and type 2) and glycaemic control and duration of disease. 6. To investigate the long-term impact of different surgical strategies (e.g. use of multiple arterial grafts or non-use of cardio-pulmonary bypass) during CABG. 7. To analyze prognosis in relevant sub-populations undergoing CABG (e.g. patients 50 years or younger, possible differences between men and women, and patients with heart failure with preserved vs. reduced ejection fraction). 8. To investigate survival and morbidity in patients between 50 and 69 years undergoing aortic valve replacement with particular reference to prosthesis type (mechanical vs. biological). 9. To analyze the association between socioeconomic factors and prognosis in patients undergoing cardiac surgery. 10. To investigate factors related to durability of bioprosthetic aortic heart valves.