Background: Coronary revascularisation by means of surgery or percutaneous intervention plays an important role in the management of patients with ischaemic heart disease. Coronary bypass surgery without cardiopulmonary bypass (off-pump surgery) has been reintroduced into clinical practice to avoid complications related to the use of cardiopulmonary bypass. It is unknown whether off-pump surgery can match the outcomes of bypass surgery with cardiopulmonary bypass (on-pump surgery) or intracoronary stent implantation.
Methods: The Octopus study comprised two multicentre randomised trials. In the Octopump trial, on-pump surgery was compared with off-pump surgery (139 vs. 142 patients). In the Octostent trial stent implantation was compared with off-pump surgery (138 vs. 142 patients). The primary cardiac endpoint was survival free from the following cardiovascular events: stroke, myocardial infarction and repeated coronary revascularisation. Secondary endpoints included quality of life and cost-effectiveness. The uncertainty surrounding the cost-effectiveness analysis was addressed by bootstrapping.
Results: Octopump trial: at one year, event-free survival in the on-pump group was 90.6% and in the off-pump group 88.0% (difference 2.6%, 95% CI-4.6 to 9.8). Quality-adjusted years of life were 0.83 and 0.82 (p=0.81), respectively. On-pump surgery was associated with €2089 (14.1%) additional direct medical costs per patient (p<0.01). Off-pump was more cost-effective than on-pump surgery in 95% of bootstrap estimates. Octostent trial: at one year, event-free survival in the stent group was 85.5% and in the off-pump surgery group 91.5% (difference -6.0%, 95% CI -13.5 to 1.4). Quality-adjusted years of life were 0.82 and 0.79 (p=0.09), respectively. Stent implantation reduced direct medical costs by €2813 (26.0%) per patient (p=0.01). Stent implantation was more cost-effective in 95% of bootstrap estimates.
Conclusion: In selected patients eligible for bypass surgery, there was no difference in cardiac outcome between on-pump and off-pump surgery. Off-pump surgery, however, was more cost-effective than on-pump surgery and may be preferred from an economic perspective. In selected patients eligible for percutaneous coronary intervention, stent implantation was more cost-effective than off-pump surgery while maintaining comparable cardiac outcome. Therefore, stent implantation rather than off-pump surgery can be recommended as a first-choice revascularisation strategy.
Keywords: bypass surgery; cost-effectiveness; off-pump; stents.