Trends in utilization of off-pump coronary artery bypass graft surgery in the US

Coronary artery bypass graft (CABG) surgery is the mainstay for surgical treatment of coronary artery disease. CABG is performed in one of two ways: (1) while the heart is temporarily arrested, and a patient receives cardiopulmonary bypass ('on pump'); or (2) without cardiopulmonary bypass with the heart still beating ('off pump'). This observational study using data from 2004-2015 from the Healthcare Cost and Utilization Project National Inpatient Sample (HCUP-NIS) examined trends in utilization and outcomes (in-hospital mortality, length of stay (LOS), hospital costs, and selected post-operative complications associated with on and off pump CABG. Overall, there was a declining trend in the number of CABG procedures. Off-pump procedure patients had significantly higher unadjusted mortality rates and longer LOS, but without significantly higher costs. There was a lower risk of post-operative stroke associated with off-pump procedures, but an increased occurrence of post-operative sepsis. One possible explanation is that more patients may be receiving angioplasty, which may have increased the pool of CABG patients with higher risk factors. Hospital administrators may use this information to optimize patient outcomes in cardiovascular surgery units. Future research should seek to control for patient level risk factors in the selection of surgical procedure.