ABC | Volume 111, Nº4, Octuber 2018

Original Article de Souza e Silva et al Percutaneous coronary intervention in the State of Rio de Janeiro Arq Bras Cardiol. 2018; 111(4):553-561 that in a follow-up of 24 months the rates of reinfarction and of subsequent target-vessel revascularization were higher in patients submitted to simple balloon angioplasty, but no difference was observed in mortality rates between the stent group and the balloon group. As for observational studies, the analysis of the New York State´s Coronary Angioplasty Reporting System data 35 showed that in-hospital mortality rates were not different between PCI with and without stent placement, but the gap between the mortality rates in the two procedures widened about six months after the procedure, favoring PCI-S, and after that the gap remained constant for a two-year follow-up. Our study also observed a higher survival rate for patients submitted to PCI-S; however, the survival rate gap between the two procedures was larger at the beginning of the follow-up, getting narrower in longer follow-up periods and, finally, from 2 to 10 years no more differences in the survival rates were observed. Therefore, after these results, future studies should be conducted to address whether PCI using drug-eluting stents shows different results when compared to bare-metal stent or simple balloon angioplasty, and whether stent placement is cost-effective against simple balloon angioplasty for the public healthcare system in the state of RJ. Finally, the death rates observed in this study are higher than those in RCTs. In a RCT conducted in the United States and in Canada with patients with stable or unstable coronary artery disease, 36 0.4% and 1.2% of the patients submitted to PCI-S and simple balloon angioplasty died, respectively, compared to 4.3% and 5.2%, respectively, in our study at 6 months of follow‑up. Boden et al. 37 showed a 7.6% cumulative death rate in 4.6 years of follow-up in patients with stable coronary artery disease submitted to PCI, (~3% with drug-eluting stent), while in our study 16.3% of the patients submitted to PCI-S died until 5 years of follow-up. In a continued follow-up of 53% of the original population from the former study, Sedlis et al. 38 showed that 25% of the patients submitted toPCI diedwithin15 years against 28.2% of deaths observed in this study. These discrepancies are likely to be explained by the problematic extrapolation of RCTs’ findings to the general population because of their restrictive inclusion and exclusion criteria. Therefore, this observational study is more likely to provide an indication of what is being achieved in the daily medical practice with a population of patients assisted by the Brazilian public healthcare system and, thus, observational studies should be deemed complementary to RCTs’ results. So, indications of PCI, especially in cases of stable IHD and in older patients, have to be questioned once the survival rates observed in such cases were lower than those expected when just clinical treatment has been used. We have to stress that the cases selected were submitted to one single procedure during the study period and they probably represent cases of better prognosis in the large spectrum of clinical presentations of IHD. Some limitations inherent to observational studies should be highlighted. The data provided were limited to those included in the AIH database. The AIH database was created for administrative purposes and hence it does not include some important clinical information such as comorbidities, medications prescribed, number of vessels affected and patients’ socioeconomic status, which might have influenced our results. Furthermore, these secondary databases did not follow strict data collection protocols and may be considered of lower quality in comparison to the data collected in RCTs. Yet, today the AIH database is the best tool available in Brazilian´s public healthcare system for this type of study due to its comprehensiveness and accessibility. Conclusion This study reports the probability of survival in 30 days, one year and 15 years of follow-up of a large number of patients submitted to one single PCI procedure paid by the Brazilian public healthcare system in the state of Rio de Janeiro. Women were prone to have a slightly lower survival probability than men in 30-day and one-year follow-up, but women had a higher survival probability within 15 years, especially when they were older. Additionally, patients submitted to PCI procedures without stent placement had a lower probability of survival within 30 days and one year, although no difference was observed after a two-year follow-up regarding the use of stents. These findings, which mirror the medical practice performed in a real-world population may help physicians make decisions regarding indicating the PCI considering the questions raised about the true benefits of this procedure. Acknowledgments Partial financial support for this study was provided by CAPES (Brazilian government). Author contributions Conception and design of the research and Analysis and interpretation of the data: de Souza e Silva CG, Klein CH, Godoy PH, Salis LHA, de Souza e Silva NA; Acquisition of data: Klein CH, Godoy PH, de Souza e Silva NA; Statistical analysis: de Souza e Silva CG, Klein CH; Writing of themanuscript: de Souza e Silva CG; Critical revision of the manuscript for intellectual content: Klein CH, Godoy PH, Salis LHA, de Souza e Silva NA. Potential Conflict of Interest No potential conflict of interest relevant to this article was reported. Sources of Funding This study was funded by CAPES. Study Association This article is part of the thesis of Doctoral submitted by Christina Grüne de Souza e Silva, from Instituto do Coração Edson Saad - Universidade Federal do Rio de Janeiro. Ethics approval and consent to participate This study was approved by the Ethics Committee of the Hospital Universitário Clementino Fraga Filho (Faculdade de Medicina – UFRJ) under the protocol number 1148/12. All the procedures in this study were in accordance with the 1975 Helsinki Declaration, updated in 2013. Informed consent was obtained from all participants included in the study. 559