ABC | Volume 111, Nº6, December 2018

Original Article The Prognostic Value and Clinical Use of Myocardial Perfusion Scintigraphy in Asymptomatic Patients after Percutaneous Coronary Intervention Larissa Franco de Andrade, 1,2 Ana Carolina Souza, 1 Thais Peclat, 1 Caio Bartholo, 1 Thalita Pavanelo, 1 Ronaldo de Souza Leão Lima 1,2 Hospital Universitário Clementino Fraga Filho - Universidade Federal do Rio de Janeiro (UFRJ), 1 Rio de Janeiro, RJ - Brazil Clínica de Diagnóstico por Imagem, 2 Rio de Janeiro, RJ – Brazil Mailing Address: Larissa Franco de Andrade • Rua Professor Rodolpho Paulo Rocco, 255 - 8°. Andar. Postal Code 21941‑913, Rio de Janeiro, RJ – Brazil E-mail: larifandrade@yahoo.com.br Manuscript received January 23, 2018, revised manscript June 04, 2018, accepted July 02, 2018 DOI: 10.5935/abc.20180199 Abstract Background: The role of myocardial perfusion scintigraphy (MPS) in the follow-up of asymptomatic patients after percutaneous coronary intervention (PCI) is not established. Objectives: To evaluate the prognostic value and clinical use of MPS in asymptomatic patients after PCI. Methods: Patients who underwent MPS consecutively between 2008 and 2012 after PCI were selected. The MPS were classified as normal and abnormal, the perfusion scores, summed stress score (SSS), and summed difference score (SDS) were calculated and converted into percentage of total perfusion defect and ischemic defect. The follow-up was undertaken through telephone interviews and consultation with the Mortality Information System. Primary endpoints were death, cardiovascular death, and nonfatal acute myocardial infarction (AMI), and secondary endpoint was revascularization. Logistic regression and COX method were used to identify the predictors of events, and the value of p < 0.05 was considered statistically significant. Results: A total of 647 patients were followed for 5.2 ± 1.6 years. 47% of MPS were normal, 30% were abnormal with ischemia, and 23%were abnormal without ischemia. There were 61 deaths, 27 being cardiovascular, 19 non‑fatal AMI, and 139 revascularizations. The annual death rate was higher in those with abnormal perfusion without ischemia compared to the groups with ischemia and normal perfusion (3.3% × 2% × 1.2%, p = 0.021). The annual revascularization rate was 10.3% in the ischemia group, 3.7% in those with normal MPS, and 3% in those with abnormal MPS without ischemia. The independent predictors of mortality and revascularization were, respectively, total perfusion defect greater than 6%, and ischemic defect greater than 3%. Forty-two percent of the patients underwent MPS less than 2 years after PCI, and no significant differences were observed in relation to those who underwent it after that period. Conclusion: Although this information is not contemplated in guidelines, in this study MPS was able to predict events in asymptomatic after PCI patients, regardless of when they were performed. (Arq Bras Cardiol. 2018; 111(6):784-793) Keywords: Myocardial Infarction; Coronary Artery Disease; Myocardial Revascularization; Heart/diagnostic imaging; Percutaneous Coronary Intervention. Introduction The coronary artery disease (CAD) is the leading cause of death in the world. 1 Percutaneous coronary intervention (PCI) is currently the most commonly used method of coronary artery revascularization in all clinical settings of CAD. 2 However, despite the technical and pharmacological changes in the last decades, patients undergoing percutaneous revascularization remain at risk of developing cardiovascular events, and the main mechanisms responsible for that are restenosis and progression of atherosclerotic disease. 3,4 Functional tests, including myocardial perfusion scintigraphy (MPS), are recommended in the evaluation of patients who develop symptoms after PCI. 2,5 In the presence of significant ischemia, a new revascularization may be proposed. In contrast, in the follow-up of asymptomatic patients, although studies have demonstrated the ability of the MPS to predict future events, 6 the guidelines do not recommend ordering routine functional tests in a period of less than 2 years, with their performance being acceptable only within this interval in specific subgroups, such as those undergoing incomplete revascularization or with prior silent ischemia, in whom a new approach is feasible. 2,5 The present study aims to evaluate the association between the clinical and scintigraphic data of asymptomatic patients submitted to MPS after PCI and the occurrence of outcomes; to estimate the prevalence of ischemia and its predictors; to evaluate the indications and MPS timing in these patients; and to compare the characteristics of the patients who underwent MPS befor and after two years of PCI. 784