Cost-effectiveness of on-pump and off-pump coronary artery bypass grafting for patients with coronary artery disease: Results from the MASS III trial

Abstract

Background: Recent trials have reported similar clinical outcomes between on-pump and off-pump coronary artery bypass graft (CABG). However, long-term cost-effectiveness of these strategies is unknown.

Methods: A prespecified economic study was performed based on the MASS III trial. Costs were estimated for all patients based on observed healthcare resource usage over a 5-year follow-up. Health state utilities were evaluated with the SF-6D questionnaire. Cost-effectiveness was assessed as cost per quality-adjusted life-year (QALY) gained using a Markov model. Probabilistic sensitivity analysis with the Monte-Carlo simulation and cost-effectiveness acceptability curve were used to address uncertainty.

Results: Quality of life improved significantly in both groups during follow-up compared with baseline. At 5 years, when comparing on-pump and off-pump CABG groups, no differences were found in cumulative life-years (4.851 and 4.766 years, P = .319) and QALY gained (4.150 and 4.105 QALYs, P = .332). Mean cost in US dollars per patient during the trial did not differ significantly between the on-pump and off-pump groups ($5890.29 and $5674.75, respectively, P = .409). Over a lifetime horizon, the incremental cost-effectiveness ratio of on-pump versus off-pump CABG was $12,576 per QALY gained, which is above the suggested cost-effectiveness threshold range (from $3210 to 10,122). In the sensitivity analysis, the probability that on-pump CABG is cost-effective compared to off-pump surgery for a willingness-to-pay threshold of $3212 per QALY gained was <1%. For the $10,122 per QALY threshold, the same probability was 35%.

Conclusion: This decision-analytic model suggests that on-pump CABG is not cost-effective when compared to off-pump CABG from a public health system perspective.

Keywords: Coronary artery disease; Cost-benefit analysis; Quality of life; Surgical revascularization.