ABC | Volume 112, Nº5, May 2019

Original Article Luciano et al Analysis of coronariographies in Southern Brazil Arq Bras Cardiol. 2019; 112(5):526-531 The results of analysis of a large retrospective cohort with 48,336 patients with suspected stable CAD in the region of Ontario, Canada, were published in 2015. 10 In the Canadian study, rates of 58.2% of appropriate cases, 31% of occasionally appropriate ones, and 10,8% of rarely appropriate cases were observed, which are similar to those found in our sample of patients being investigated for CAD, with 54.7% classified as appropriate, 35.1% occasionally appropriate, and 10.2% rarely appropriate. Despite the apparent balance in the proportion of indications, while 18.9% of the patients classified as rarely appropriate in the Canadian study underwent revascularization procedures, 100% of the patients so classified in our study were referred for clinical treatment despite the presence of severe coronary lesions. This can be explained by the presence of distal lesions in thin or minor vessels that make clinical treatment the best option in this context. This information validates the application of the guideline in our population, since patients with an indication of rarely appropriate for coronary angiography would not have an indication of treatment of revascularization as a complement to the optimal drug therapy. Another large retrospective study in the state of New York analyzed the indications of 8,986 coronary angiographies, and found that 24.9% of their cases were classified as rarely appropriate, 9 a number that is considerably larger than the 10.8% and 10.2% in the Canadian study and in our sample, respectively. To explain why about a quarter of cases were classified as rarely appropriate, it was argued that at the time of coronary angiography, the 2012 guideline for the appropriate use of diagnostic cardiac catheterization had not yet been published. However, the situation is similar to that of the Canadian cohort, which had its coronary angiograms performed between 2008 and 2011, and presented more modest proportions of rarely appropriate coronary angiograms. A significant portion of the rarely appropriate coronary angiographies enters this classification due to non-performance of previous functional tests, 16,17 a situation that is responsible for 56.2% of these cases in our sample. The performance of functional tests would provide the reclassification of these cases, improving the use of coronary angiography. 6,17,18 When we observed the differences between the two institutions involved in the present study, a higher proportion of coronary angiographies with appropriate indication at Hospital B, and a higher proportion of occasionally appropriate at Hospital A (Table 3) were evident in the subgroup of patients being investigated for CAD. The highest proportion of preoperative cardiac surgery tests performed at Hospital B, an indication classified as appropriate by the guideline, 6 explains part of this difference. The performance of cardiac surgeries in Hospital B, an institution dedicated to cardiology, appears as the main factor for the difference of appropriation between the two institutions. The limitations of our study are the reduced size of its sample, which precludes a detailed analysis of each indication of the guideline; and failure to follow patients for prognostic evaluation related to outcome and treatment. In addition, more than 50% of our sample are cases of ACS, in which invasive stratification is appropriate according to the guideline, limiting the analysis of the quality of the indication in this scenario. The results represent the reality of the patients treated in two public hospitals located in the southern region of Brazil. Further studies are necessary to evaluate the indications of coronary angiography in other contexts and regions of the country. Conclusion We conclude that our sample has appropriation indices similar to those in the literature, with a small rate of rarely appropriate procedures. The guideline recommendation in rarely appropriate cases was adequate in our study, with no patients in this group requiring revascularization treatment. Most of these cases are due to non-performance of previous functional tests. The difference between the two hospitals, a general and a cardiology hospital, was inherent in the population served, with similar adjusted appropriate use rates. Author contributions Conception and design of the research: Luciano LSC, da Silva RL; Acquisition of data: Luciano LSC, da Silva RL, Waldrich L, Panata L, Preve JC, Fattah T, Giuliano LC, Thiago LEKS; Analysis and interpretation of the data: Luciano LSC, da Silva RL, Londero Filho OM; Statistical analysis: Luciano LSC, da Silva RL, Trombetta AP;Writing of the manuscript: Luciano LSC, da Silva RL; Critical revision of the manuscript for intellectual content: Luciano LSC, da Silva RL, Londero Filho OM, Trombetta AP, Preve JC, Giuliano LC, Thiago LEKS. Potential Conflict of Interest No potential conflict of interest relevant to this article was reported. Sources of Funding There were no external funding sources for this study. Study Association This study is not associatedwith any thesis or dissertationwork. Ethics approval and consent to participate This study was approved by the Ethics Committee of the Instituto de Cardiologia de Santa Catarina under the protocol number CAAE 83732218.8.0000.0113. All the procedures in this study were in accordance with the 1975 Helsinki Declaration, updated in 2013. As it was not an experimental study, the informed consent was dispensed by the Ethics Committee. 530