ABC | Volume 111, Nº6, December 2018

Original Article Andrade et al Prognostic Value of Myocardial Scintigraphy Arq Bras Cardiol. 2018; 111(6):784-793 Methods Population Among the 6,698 MPS that were consecutively performed at the Clínica de diagnóstico por imagem in Rio de Janeiro from March 2008 to November 2012, 1,220 patient exams were identified as previously undergoing PCI. Of these, 322 were excluded because the patients had symptoms at the time of the exam, and 186 because they had already undergone a revascularization surgery. Forty-six patients underwent more than one exam in the period and, in those cases, only the first exam was considered. Thus, 647 patients were enrolled in the study, as shown in figure 1. The study was approved by the Ethics and Research Committee of the Hospital Clementino Fraga Filho, and each patient signed a consent form to include their information in the database, including clinical characteristics and the data of the examination. Image protocol MPS were performed using the 2-day protocol. In the resting phase, a dose of 20mCi 99 mTc-sestamibi was injected with acquisition of the images after 30 to 40 minutes, and in the stress phase a dose of 20mCi of 99 mTc-sestamibi was injected during the exercise test or pharmacological stress test, and image acquisition was performed after 15 to 30 minutes. The physical and pharmacological stress protocols were performed as described in a previous study. 7 MPS images were acquired through the gated-SPECT technique in the Ventri gamma-camera, GE Healthcare. The exams were classified as normal, or with reversible, fixed or mixed perfusion defects. The semi-quantitative visual analysis was independently performed by two cardiologists with extensive experience, through the standard 17-segment model, in which the quantification of radiotracer uptake was evaluated in each segment, graduated on a scale of 0 to 4, where 0 = normal uptake; 1 = slight reduction of uptake; 2 = moderate reduction of uptake, 3 = severe reduction of uptake; 4 = no uptake. 8 The values attributed to each of the 17 segments were added in the stress phase, called summed stress score (SSS), and in the resting phase, called summed rest score (SRS). The difference between these two scores is called summed difference score (SDS), and represents the degree of transient reversibility. Abnormal MPS was defined by SSS > 3, and abnormal MPS with ischemia by SDS > 1. SSS and SDS were converted, respectively, into percent of total perfusion defect and ischemic defect by dividing the score by 68 (maximum value of the score) and then multiplying by 100. The ejection fraction (EF) and the left ventricular diastolic and systolic volumes were measured automatically using the software. Follow-up Patients’ follow-up was carried out through biannual telephone interviews and application of a standardized Figure 1 – Flow chart of patient selection. PCI: percutaneous coronary intervention; MPS: myocardial perfusion scintigraphy. 6698 MPS were performed between 2008-2012 Inclusion criteria: previous PCI 1220 MPS were selected Exclusion criteria: 322 had symptoms 186 had previous surgical revascularization 702 MPS were selected 647 eligible patients 37 patients had 2 exams 9 patients had 3 exams 785