Propensity matched comparison of outcomes in older and younger patients after coronary artery bypass graft surgery

Background. By 2050, the number of people in the United States aged 85 years and older is expected to increase from 4.2 to 20.8 million. We therefore compared outcomes after isolated coronary artery bypass grafting (CABG) in patients aged 85 years and older with those 55 to 65 years old. Methods. Propensity matching and multivariable analysis were used to compare morbidity and mortality outcomes in 132 patients aged 85 years and older and in 5243 patients aged 55 to 65 years who underwent CABG between 1993 and 2004. Variables of interest were compared using Student t, Wilcoxon rank sum, chi(2), or Fischer exact tests, as appropriate. Results. After propensity matching, each group had 122 patients who were matched on all baseline and intraoperative variables except number of intraoperative red blood cell (RBC) transfusions, which was greater in the older group. Atrial arrhythmias occurred more frequently and intensive care unit (ICU) and hospital lengths of stay (LOS) were longer in the older group. Multiple logistic regression analysis demonstrated that atrial arrhythmias and catheter-related sepsis were more common in the older group. Conclusions. Older patients received more RBC transfusions, presumably reflecting a lower threshold to transfuse older patients. Atrial arrhythmias were more common in the older group, this can account for their longer ICU and hospital LOS, which can also explain their greater incidence of catheter sepsis. The two age groups had similar mortality and morbidity. Advanced age is not associated with substantively worse outcome after CABG compared with a propensity-matched younger age group.