The costs of on- and off-pump CABG are similar at one year, according to an analysis of the ROOBY study, but only if late conversions are excluded. Including late conversions elevated off-pump CABG costs by $3,600. The results were presented as a late-breaking clinical trial abstract on Jan. 28 at the Society for Thoracic Surgeons (STS) meeting in Los Angeles.
The ROOBY (Veterans Affairs Randomized On/Off Bypass) study enrolled 2,203 patients scheduled to undergo elective or urgent CABG to either on- or off-pump CABG to evaluate outcomes in major morbidity and mortality at 30 days and one year postprocedure. The ROOBY researchers found at one-year follow-up a higher rate of the composite outcome of death or major complications (reoperation, new mechanical support, cardiac arrest, coma, stroke or renal failure requiring dialysis) and poorer graft patency in the off-pump group (New Engl J Med 2009;361:1827-1837).
Of the 1,104 patients in this study in the off-pump group, 137 were converted to on-pump. In the 1,099-patient on-pump group, 43 were converted to off-pump.
Annie Laurie Shroyer, PhD, of the Northport Veterans Affairs Medical Center in Northport, N.Y., and colleagues designed this follow-up cost-effectiveness study to compare one-year quality-adjusted life years and costs. Todd Wagner, PhD, a health economist at the Veterans Affairs Palo Alto Health Care System in Menlo Park, Calif., presented the findings for the study group. They used multivariate cost-effectiveness analysis regression models to calculate one-year costs in 2010 U.S. dollars and controlled for patient and site factors.
The researchers found no difference in quality-adjusted life years and both groups showed improvement postoperatively. The adjusted index hospitalization costs were slightly higher in the off-pump group, at $36,536 vs. $36,048 in the on-pump group. Mean surgery costs were about $500 more in the off-pump group.
Unadjusted postprocedure discharge costs at one-year follow-up were also higher in the off-pump group, at $21,015 vs. $18,045 on-pump, as were total costs, at $59,859 for off-pump vs. $56,367 for on-pump.
Mean adjusted one-year costs totaled $57,951 in the off-pump group and $56,127 in the on-pump group when conversions were excluded but were $59,623 vs. $56,023 without the exclusion. The study team recommended additional research to evaluate the potential cost-effectiveness benefit of off-pump CABG.