ABC | Volume 112, Nº1, January 2019

Original Article Quintella et al FFR-versus angiography-guided PCI in multivessel disease Arq Bras Cardiol. 2019; 112(1):40-47 These results contrast with those reported in the FAME study, 15 probably because only PS (without inclusion of NPS) was used by the authors. In addition, we could speculate that, considering the use of NPS in patients with multivessel diseases, the choice for FFR could provide additional benefit. Since the incidence of restenosis was higher in this population, although the percentages of lesions did not differ with the use of PS, there was a significant reduction in the total number of lesions, in absolute numbers, as described as follows: For NPS: Situation 1: considering a hypothetical restenosis rate of 20%, there will be 20 restenosis for every 100 lesions considered significant according to angiographic criteria. Situation 2: for every 100 lesions functionally analyzed, 50 will be treated; considering the same hypothetical restenosis rate of 20%, there will be 10 restenosis. For PS: Situation 1: considering a hypothetical restenosis rate of 5%, there will be 5 restenosis for every 100 lesions considered significant according to angiographic criteria. Situation 2: for every 100 lesions functionally analyzed, 50 will be treated; considering the same hypothetical restenosis rate of 5%, there will be 2.5 restenosis. Thus, the use of functional analysis to determine the likelihood of recommending revascularization could prevent more restenosis (in absolute numbers) than NPS. Considering TLR, only half of patients of the FFR group underwent another PCI, whereas in the ANGIO group, the number of vessels treated was six times greater and the need for TLR was twice higher. These findings differ from those reported in the FAME study, 15 again, probably because only PS was used in their study. Logistic regression of demographic, clinical and angiographical factors did not show increased risk for MACE, similar to the FAME study. 15 Angiographic data In the FFR group, 45% of the lesions analyzed were treated, with a mean of 1.14 stent per patient; in the ANGIO group, all lesions were treated, with a mean of 2.2 stents per patient. The number of stents was 50% greater in the ANGIO group. In the FAME 15 study, however, only 30% of the lesions were treated (2.7 stents per patient in the ANGIO group and 1.9 in the FFR group). The mean extension of stent coverage was 51.4 ± 2.0 mm and 37.9 ± 27.0 mm, respectively, 15 and in our study we found a mean of 14.65 ± 6.91 mm. The mean FFR was 0.74 ± 0.15 mm in our study, very similar to that of the FAME study. 15 Based on functional analysis, 55% and 37% of the lesions analyzed were not treated in the present study and in the FAME study, 15 respectively; this difference may be due to the inclusion of more complex lesions treated by PS in our study. In addition, although mean stenosis percentage (60%) was similar in both studies, mean diameter of target vessel was greater in our study (2.9 ± 0.4 mm and 2,8 ± 0,5 mm in FFR and ANGIO groups, respectively) compared with the FAME study 15 (mean of 2.5 mm in both groups). Cost-effectiveness CE compares costs and effects of different health technologies to identify which technique provides the greatest benefit, and the incremental cost (IC) for it. In this economic analysis, costs are expressed in monetary units, whereas effects in clinical-epidemiological units or natural units (prevented cases, survival, cure, etc.). The main of CE analysis is to maximize the outcomes in health with the financial resources available. The most common outcome measure of CE analysis is ICER, which represents the ratio between costs of the techniques (cost of A – cost of B) and effectiveness of the techniques (effectiveness of A – effectiveness of B). This ratio is used to identify which of these strategies result in maximal effectiveness for a given cost, or the degree of investment required to obtain incremental benefit in health. CE criterion is one of many criteria that should be used to determine whether an intervention should be offered. In addition, equity, needs and priorities should also be considered in the decision-making process. CE relates costs with clinical outcomes and compare relative value of interventions; it translates the difference of costs between two strategies of treatment. The monetary value is divided by the difference of their effectiveness, expressed in years of life gained (life expectancy) or other prevented or avoided events. 21 Quality-adjusted life year (QALY) is a measure of disease burden, of both quality and quantity of life. QALY is used to evaluate the cost-benefit ratio of a therapeutic intervention. 21 In monetary values, therapies with costs lower than USD20,000/QALY are considered favorable strategies; those with costs from USD20,000 to USD40,000/QALY are consistent with habitual interventions, and therapies with costs higher than USD40,000/QALY are considered of little benefit. CE of an intervention is known to vary with overall individual or population risk; 21 however, in Brazil, the incremental costs of an intervention that provide clinical benefits have not been established. In both American and Canadian health systems, the value of USD50,000 per QALY, and more recently USD10,000 per prevented major event is considered a reasonable utilization of health resources. In the present study, the difference of effectiveness in one year was 1.82%; however, ICER, established as the difference of costs between PCI in the ANGIO group and PCI in the FFR group divided by the difference in effectiveness (one-year-restenosis- free survival) was BRL21,156.55. This value is consistent with optimal therapies as well as with overall individual or population risk, and therefore considered cost-effective. We did not find in the literature studies on the CE of FFR-guided PCI and NPS in patients with multivessel diseases, which is hence a strength of our study. Our findings demonstrate clinical benefits of CE during one year of follow‑up, which is not commonly seen in new therapeutic strategies, as shown by Fearon et al., 22 suggesting an economic or social impact. The use of FFR in PCI in multivessel disease patients is a more cost-effective approach than treating all significant lesions identified by angiography. This can help change the paradigm and reduce costs 23 at the same time and thereby consolidate the practice of medicine based on physiological data, which would lead to better medical care. 45