[Intracoronary prosthesis (stent): an approach to the analysis of cost-effectiveness]

Stents have emerged as one of the major therapeutic tools for percutaneous intracoronary revascularization procedures. In fact, a stent is implanted in at least 30% of lesions attempted. Their clinical impact is huge because stenting has produced a decrease int the need for emergency surgery to 0.5%, with an incidence of acute myocardial infarction related to angioplasty of 2% and a death rate of < 1% despite unfavourable clinical and anatomical conditions treated. The initial price of stenting was a high frequency of subacute stent thrombosis and peripheral vascular complications, which has been solved. In this context, the cost of stenting procedures increased by more than 30% in relation to the cost of conventional balloon angioplasty. But, the use of new antiplatelet regimes, implantation with high atmospheres and the achievement of a minimal residual narrowing after stenting practically promotes the disappearance of the two major initial problems, making possible a decrease in the restenosis rate to 20% with a parallel reduction of 10% in the need for new revascularization procedures during the first years after stent implantation. This means a reduction in the midterm costs. The incremental rate of cost/effectiveness after stenting in one vessel disease has been estimated as 23,600 dollars/years of adjusted quality of life gained ($/QUALY) ($20-40,000/QALY is acceptable in pharmaeconomic studies). From another point of view, stenting implies 19 QALYS gained at a mean cost of $52,700. The incremental cost of stenting may be more favourable if a reduction of $1,800 in the total cost of stenting procedures could be achieved, or if the stent cost were reduced by at least $700. In Spain, each patient who was event-free during the first year of follow-up would cost 1,674,000 ptas. A 10% reduction of new revascularization procedures x 100 patients would cost 20 million pesetas. Despite the enormous interest of socioeconomic analysis these data only reflect a partial point of view, because of the complexity of evaluating the contribution of new technologies, the true quality of life gained for patients, the societal point of view, or that of the National Health Service. Moreover, we assume that in the current socioeconomic context there are finite resources and a limitless demand.