OBJECTIVES: Endeavor combines the Driver stent, the drug ABT-578 and a PC polymer into a new drug-eluting coronary artery stent (DES) system. As results from long-term trials of Endeavor are not yet available, economic modelling techniques must be employed to evaluate the cost-effectiveness of this new treatment option. The study undertook the first assessment of the cost-effectiveness of Endeavor DES, compared to the Driver bare-metal stent (BMS), in the treatment of de novo lesions in native coronary arteries. METHODS: A Markov model was developed simulating the results of the ENDEAVOR II trial at nine months follow-up, and extrapolating to five years using the BENESTENT I trial. No difference was assumed between the outcomes with the two stents after the first year. The events modelled were target vessel revascularisations, AMIs, cerebrovascular accidents and death. The expected costs were calculated for 2005 from the perspective of the UK NHS. Each event was associated with a transient decrement in health-related utility due to recurrent symptoms while waiting for a repeat intervention and to pain and distress of events or further interventions, relative to a baseline asymptomatic coronary heart disease value based on the ARTS and SoS trials. A probabilistic sensitivity analysis was undertaken. RESULTS: Although the price premium of Endeavor is above £500, the total cost of Endeavor treatment was only slightly higher at 5 years than Driver (£6,094 vs £6,058) due mainly to the reduced need for revascularisations in the first year. Endeavor was also associated with QALY gains (0.0053 per patient), and therefore had an incremental cost-effectiveness ratio of ~ £6,700/QALY. The probability of Endeavor being cost-effective at a threshold of £30,000/QALY was 58%. CONCLUSIONS: This exploratory analysis shows the Endeavor DES to be cost-effective. Results of long-term trials are awaited to confirm model predictions.