Questão simples, resposta multivariada

Abstract

Discussion of the cost-effectiveness analysis of drugeluting stents (DES) is both extremely important and necessary, although challenging. Perhaps this urgency contradicts what research has recently demonstrated regarding such devices: the obvious clinical bene fit of DES in all analysed subgroups in randomised experimental scenarios and in real patients.1,2 This year marked the tenth anniversary of the use of this groundbreaking technology in our field. Several studies have shown both the efficacy and safety of these devices for coronary restenosis reduction compared with bare-metal stents (BMS).3-5 Data favouring their use have led to increased deployment. Cardiologists must consider the novelty and high cost of this technology; conversely, they must consider the undeniable benefits it provides. The question must be asked: is this treatment cost-effective? See page 21In the study published in this issue of the Revista Brasileira de Cardiologia Invasiva, Ferreira et al. 6 compared the performance of the Taxus ® DES and the Liberté ® BMS in consecutive, non-randomised patients. Even in countries where the DES/BMS relationship is not as heavily promoted as in this sample, and despite the reduction of restenosis with DES in all subgroups analysed, the development of a model of maximal benefits is necessary. In one of these recently published models, 7 the number needed to treat (NNT) with DES to avoid new revascularisation of the target vessel ranged from 6 to 80. This finding means that in certain subgroups, restenosis with BMS was so low that it would be necessary to treat 80 patients with DES in order to avoid a new procedure. Conversely, in other subgroups, restenosis with BMS was high, and the NNT with DES to avoid a new procedure was only 6. These concepts generate a proper discussion regarding the moment at which a decision must be made, and the clinician must compare the clinical benefit of using a device versus public health policies in order to optimize the incorporation of new technologies.The cost-effectiveness concept can be defined as the difference between the cost of the two interventions, expressed in monetary value, divided by the diffe rence between their effectiveness, expressed in years of life gained (life expectancy) or in order less important outcomes, such as the number of prevented complications and the number of averted non-fatal events.8 Regarding BMS, the following question must be asked: what is the additional cost for each new averted revascularisation? In Brazil, the values obtained in order to avoid either a new revascularisation or an event in the target vessel were R$ 47,000 in the analysis by Polanczyk et al.,