OBJECTIVES: Off-pump CABG (OPCAB) has been shown to be as safe and effective as on-pump CABG (ONCAB). Despite recent evidence demonstrating that OPCAB carries multiple patient-centered benefits, the volume of OPCAB surgeries over the last decade has decreased, and there are few studies estimating the cost-effectiveness of OPCAB. The purpose of this study was to determine whether OPCAB was cost-effective relative to ONCAB using a national sample.

METHODS: Using data from the National Inpatient Sample, we studied 666,884 patients who underwent CABG between 2004 and 2015 in the US. Costs were estimated from a health system perspective and adjusted for inflation to 2018 US dollars. The outcome measure was in-patient mortality. Cost-effectiveness was measured as the incremental cost-effectiveness ratio (ICER), which was measured as the additional cost to save one additional life using OPCAB. Uncertainty around the ICER was quantified using a 95% confidence ellipse estimated using bootstrapping. We also estimated cost-effectiveness acceptability curves (CEAC), which estimate the probability OPCAB was cost-effective across a range of willingness-to-pay thresholds. Sensitivity analyses were undertaken by computing the ICER and CEAC across strata of patient, disease, and hospital characteristics.

RESULTS: Among patients receiving CABG surgery, 176,739 (26.5%) received OPCAB. Across all years, the expected cost for OPCAB was $44,130, compared to $44,098 for ONCAB. The expected survival was 97.94% for OPCAB, compared to 98.35% for ONCAB, which means that OPCAB was dominated by ONCAB. Over time, OPCAB became relatively more cost-effective but never achieved an ICER that represented good value compared to ONCAB. However, OPCAB was cost-effective in Asian and Hispanic ethnicity and commercial payers.

CONCLUSIONS: Historically, OPCAB does not appear to be cost-effective relative to ONCAB. Overall, OPCAB was more costly but less effective than ONCAB; in about half of sensitivity analyses OPCAB was less costly but less effective than ONCAB.