In-hospital mortality in cardiac surgery patients after readmission to the intensive care unit: a single-center experience with 10,992 patients.

OBJECTIVES: Determine if readmission to the intensive care unit (ICU) after cardiac surgery procedures is associated with increased mortality.
DESIGN: This was a retrospective non-randomized study to evaluate the cause of readmission and mortality rate in patients readmitted to the ICU after cardiac surgery and to compare the clinical variables of patients readmitted to the ICU who died and those who survived.
SETTING: The study was performed in a single university hospital. PARTICIPANTS: This was an analysis of 10,992 consecutive adult patients. Readmission rate to the ICU, mortality rate, the reason for readmission to the ICU, type of surgery, length of stay, cause of mortality, and day of the week of ICU readmission were analyzed.
INTERVENTIONS: All patients underwent cardiac surgery at a single center and were discharged after primary stay from the ICU.
MEASUREMENTS AND MAIN RESULTS: A total of 197 (1,8%) of 10,992 patients were readmitted to the ICU. In-hospital mortality rate for patients readmitted and not readmitted to the ICU was 23.9% and 4.7%, respectively. The main causes of ICU readmission were cardiac (40%) and respiratory (37%) complications. The mortality rate in readmitted patients who underwent coronary artery bypass graft (CABG) or valve surgery was 26% and 19%, respectively.
CONCLUSIONS: Patient readmission to the ICU following cardiac surgery was associated with a 5-fold increase in hospital mortality rate compared to non-readmitted patients. The highest mortality rate was observed among readmitted patients who underwent CABG. Older age, previous myocardial infarction, and initial long length of stay in the post-operative ward were independent risk factors for death after readmission to the ICU.