Revascularização miocárdica em multiarteriais

Abstract

led us to believe that such objectives were better achieved with surgery, especially when indicated to patients with a lesion in the left main coronary artery, three-vessel disease or ventricular dysfunction. Great advances in clinical (statins, potent antiplatelet agents) and surgical (greater use of arterial grafts, better myocardial protection, procedures without extracorporeal circulation) therapy have occurred, resulting in an undeniable improvement in the prognosis of those patients. In recent years, percutaneous transluminal coronary angioplasty has become the most common form of myocardial revascularization used for the treatment of coronary artery disease. The improvement in the techniques and instruments allowed such less invasive form of revascularization to be offered to patients with multivessel disease with safety and efficacy similar to those of surgical revascularization reported in several studies. Silva et al 4 have reported the results of a randomized study carried out in a single center in our country, assessing the long-term advantages of both strategies of revascularization regarding the clinical evolution of patients with multivessel coronary disease. The first case series, published in the 1990s, compared coronary artery bypass surgery with balloon-catheter coronary angioplasty 5-12 . Those studies showed in a uniform way that the mortality and infarction rates did not statistically differ between the 2 forms of treatment (fig.1); patients undergoing the percutaneous coronary intervention, however, more often required a new revascularization in the long run, due to the occurrence of restenosis. Although those studies had limitations regarding the selection of patients (inclusion of patients with one-vessel disease, clinical and angiographic differences between the populations), they confirmed the safety of coronary angioplasty and its indication to patients with one- or two-vessel disease and less complex lesions. Initially used for managing complications of angioplasty (acute occlusions, vessel dissections), the implantation of coronary stents has become frequent and has been recommended due to their mechanical properties of preventing elastic recoil and negative remodeling of the vascular wall, which are determinant factors in the process of coronary restenosis after balloon angioplasty. By reducing the occurrence of restenosis and acute complications, stent implantation produced results even closer to those obtained with surgery. A meta-analysis 13 comparing coronary artery bypass graft with percutaneous transluminal coronary angioplasty involving 2,643 patients and comprising the ARTS 14 , ERACI II 15 , and SOS 16 studies showed no difference in the mortality and non-fatal infarction rates between the 2 groups at the end of one year. The need for a new revascularization in the group undergoing percutaneous transluminal coronary angioplasty with stents was 15%, half of the incidence reported for balloon angioplasty in patients with multivessel disease. The indices of new revascularization, however, continued significantly greater than those of coronary artery bypass graft, mainly due to intra-stent restenosis. The article by Silva et al 4 corroborated those results: the combined-event-free survival in 5 years reported in the study in question (82% for the surgical group, and 55% for the PTCA group, P < 0.001) was similar to that reported in the ARTS I study for the same follow-up period (tab. I) 17 . We face a new era in the percutaneous treatment of coronary artery disease. The use of stents coated with antiproliferative drugs, carried and released in a controlled way in the vascular wall from biocompatible polymers proved effective in reducing neointimal hyperplasia, which is the major determinant of the occurrence of intra-stent restenosis. Since the first clinical use of sirolimus-eluting stents here in Brazil 18