[Health-economic modeling on the use of drug-eluting stents versus coronary artery bypass graft surgery in coronary heart disease].

BACKGROUND AND PURPOSE

The therapy of coronary heart disease (CHD) leads to an enormous economic burden on health-care systems. Coronary artery bypass grafting (CABG) and percutaneous revascularizations with implantation of drug-eluting stents (DES) are important treatment methods in CHD. The presented evaluation addresses cost efficacy of the use of DES versus CABG in CHD patients.

METHODS

A health-economic model considering linear resource use was performed from a restricted societal perspective for time periods of 1 and 3 years. Because of the short time horizon discounting was not applied. The clinical assumptions for event rates at 1 and 3 years were derived from the ARTS-I study for CABG, and from the ARTS-II study for DES (sirolimus-eluting stents). Cost assumptions for the resources used were based on the German Diagnosis Related Groups 2007 (G-DRG-2007). The base case value was assumed to be 2,800 Euros, the average DES price 1,200 Euros, and the average DES use per patient 3.7. The average per-patient daily clopidogrel costs were assumed to be 2.57 Euros, and the duration of the clopidogrel therapy 12 months. Within the scope of sensitivity analyses, different model parameters were varied and the evaluation was tested for its robustness.

RESULTS

The average costs for percutaneous coronary intervention (PCI) without DES were found to be 4,420 Euros, for CABG 12,840 Euros, and for DES intervention 8,860 Euros (Table 4). 1-year clopidogrel intake resulted in 938 Euros, the treatment of patients with myocardial infarction during follow-up in 3,989 Euros. The 1-year per-patient total costs after CABG were calculated to be 13,373 Euros and after DES 10,443 Euros, leading to a difference of 2,930 Euros in favor of DES implantation (Table 6). The 3-year per-patient total costs after CABG were estimated to be 13,630 Euros and after DES 10,905 Euros, showing a Rehabilitationsmasscost difference of 2,725 Euros in favor of DES implantation (Table 6). Changes in cost-weights of G-DRG-2007 for CABG and PCI, DES price and DES use per patient as well as in the duration of the clopidogrel therapy influenced the cost differences considerably; however, they did not reach a break-even point (Figures 2 and 3). Changes in the clinical follow-up assumptions showed a lower effect on the difference in total costs (Figures 2 and 3).

CONCLUSION

The presented data, indicating a possible economic middle-term advantage of DES versus CABG, should be proven with clinical assumptions derived from randomized clinical trials.