Costs Five Years After Off-Pump or On-Pump Coronary Artery Bypass Surgery

Abstract

Coronary artery bypass grafting (CABG) is a common surgical treatment for ischemic heart disease. Little is known about the long-term costs of conducting the surgery on-pump or off-pump. As part of the Randomized On/Off Bypass follow-up study, we followed 2,203 participants randomized to on-pump (n= 1,099) and off-pump (n= 1,104) CABG for 5 years using Department of Veterans Affairs and Medicare administrative data. We examined annual costs through 5 years, standardized to 2016 dollars, using multivariate regression models, controlling for site and baseline patient factors. In the first year, including the CABG surgery, annual average costs were $66,599 (SE, $1,946) for the on-pump group and $70,552 (SE, $1,954) for the off-pump group. In years 2 to 5, average costs ranged from $15,000 to $20,000 per year. There was no significant difference between on-pump and off-pump across the 5 years. We explored differences among high-risk subgroups (diabetes, chronic obstructive pulmonary disease, peripheral vascular disease, cerebrovascular disease, renal dysfunction, ejection fraction < 35%, over age 70 years), and found no treatment assignment by time interactions, except for a nonsignificant trend in patients with diabetes. At 5 years, the average costs of off-pump and on-pump CABG patients did not statistically differ. Costs do not favor one approach and the decision should be based on clinical risks, especially in subgroups. Future research is warranted to examine post-CABG costs and outcomes for diabetic patients over time.