Data Collection and Variable Definition
Baseline information, operative and postoperative data were distracted from the inpatient records system. The examination results closest to surgery date were recorded. Low cardiac output syndrome was defined as supported by large doses of cardiovascular active drugs and mechanical equipment including intra-aortic balloon pump and extracorporeal membrane oxygenation. Respiratory complications were considered if any of the following conditions were met: 1) lung infection and pathogenic culture positive twice; 2) ventilation support more than 7 days when the heart function was good. Poor wound healing referred to the need for debridement.