IJCS | Volume 31, Nº4, July / August 2018

337 1. Sant’Anna FM, Brito MB. Fractional flow reserve: concepts and application. Rev SOCERJ. 2009;22(1):43-55. 2. Mattos LA, Lemos Neto PA, Rassi A Jr, Marin-Neto JA, Sousa AG, Devito FS, et al; Sociedade Brasileira de Cardiologia. Diretrizes da Sociedade Brasileira de Cardiologia – Intervenção coronária percutânea e métodos adjuntos diagnósticos em cardiologia intervencionista (II Edição – 2008). Arq Bras Cardiol. 2008;91(6 supl.1):1-58. 3. Pijls NH, Fearon WF, Tonino PA, Siebert U, Ikeno F, Bornschein B, et al; FAME Study Investigators. Fractional flowreserve versus angiography for guiding percutaneous coronary intervention in patients with multivessel coronary artery disease: 2-year follow-up of the FAME (Fractional Flow Reserve Versus Angiography forMultivessel Evaluation) study. J AmColl Cardiol. 2010;56(3):177-84. doi: 10.1016/j.jacc.2010.04.012. 4. Cesar LA, Ferreira JF, Armaganijan D, Gowdak LH, Mansur AP, Bodanese LC et al; Sociedade Brasileira de Cardiologia. Guideline for References other invasive evaluations can be performed to better quantify the microvascular disease. The coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) improve risk stratification in patients with negative FFR, being an independent prognostic factor. 11-13 The CFR represents the vasodilation capacity of the coronary vascular bed during hyperemia, being measured by thermodilution indicators. A lowCFR value (≤ 2) indicates microvascular dysfunction. Additionally, the microvascular resistance index also provides data on microvascular function, being measured by through the distal coronary pressure multiplied by the mean transit time of 3 mL of saline bolus during adenosine-induced hyperemia, with the normal value being < 20, whereas the altered value is > 30. 11-13 In the total sample, the FFR was negative in 53.57% of the patients who had a positive MPS, a result that can be explained by the presence of microvascular disease, which was confirmed by the abovementioned methods. No significant agreement was observed in the ADA- specific analysis, but 83% of the patients with negative scintigraphy also had a negative FFR. There was no significant data on agreement or disagreement in our sample, possibly due to the number of patients studied, requiring that a larger sample be assessed. Conclusion Disagreements may occur between the functional analysis results of moderate coronary lesions by invasive and non-invasive tests. This fact can have important consequences in the use of the scintigraphy to establish the optimal revascularization strategy, mainly in multivessel patients. Therefore, fractional flow reserve is good technique to be used together with coronary angiography, especially in patients with multivessel lesions, since anatomic and functional stratifications can be obtained in a single procedure. Regarding patients with microvascular disease, the fractional flow reserve is not defined as an ideal strategy to evaluate ischemia. Author contributions Conception and design of the research: Pittella F, Paço P, Leandro SM, Felix R, Issa AFC. Acquisition of data: Paço P, Leandro SM, Tadeu J, Felix R, Issa AFC. Analysis and interpretation of the data: Pittella F, Paço P, Tadeu J, Felix R, Issa AFC. Statistical analysis: Paço P, Issa AFC. Writing of the manuscript: Paço P, Issa AFC. Critical revision of themanuscript for intellectual content: Pittella F, Felix R, Issa AFC. Supervision / as the major investigador: Leandro SM, Felix R, Issa AFC. Conducting examinations: Leandro SM, Felix R. 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 associated with any thesis or dissertation work. Ethics approval and consent to participate This study was approved by the Ethics Committee of the Instituto Nacional de Cardiologia under the protocol number 5272. 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. Issa et al. Comparison between Fraction Flow Reserve and SPECT in Myocardial Ischemia Int J Cardiovasc Sci. 2018;31(4)333-338 Original Article