Long-Term Outcome and Predictors of Noninstitutionalized Survival Subsequent to Prolonged Intensive Care Unit Stay After Cardiac Surgical Procedures

Background There are minimal data on long-term functional survival (alive and not institutionalized) in patients undergoing cardiac operations who require a prolonged intensive care unit length of stay (prICULOS). We sought to describe 1- and 5-year functional survival in patients who had a prICULOS (ICULOS ≥ 5 days) and determine predictors of functional survival at 1 year. Methods Data were obtained from linked clinical and administrative databases from January 1, 2000 to December 31, 2011 to conduct this retrospective single-region analysis. Logistic regression was used to develop a model predicting functional survival at 1 year for patients who had a prICULOS after cardiac operations. Results There were 9,545 admissions to the ICU after cardiac operations; of these patients, 728 (7.6%) experienced a prICULOS. There was an increasing trend in patients who had a prICULOS over this study period. The functional survival at 1 and 5 years from the surgical procedure for the non-prICULOS versus the prICULOS cohort was 1 year (94.9% versus 73.9%) and 5 years (84.9% versus 53.8%) ( p < 0.001). Factors associated with lower rates of functional survival at 1 year were age 80 years or older, female sex, peripheral vascular disease, preoperative renal dysfunction, cerebrovascular disease, preoperative infection, need for extracorporeal membrane oxygenation/ventricular assist device (ECMO/VAD) after cardiotomy, number of days on mechanical ventilation, and number of days in the ICU beyond 5 days (area under the receiver operating characteristic [ROC] curve = 0.766). Conclusions The majority of patients who had a prICULOS experienced successful functional survival up to 5 years after cardiac operations. Identification of risk factors for poor functional survival may be of assistance to clinicians, patients, and families for prognostication and decision making.