ABC | Volume 112, Nº2, February 2019

Original Article Study of Myocardial Perfusion in Obese Individuals without Known Ischemic Heart Disease Tufi Dippe Jr., 1 Cláudio Leinig Pereira da Cunha, 1 Rodrigo Julio Cerci, 2 Arnaldo Lafitte Stier Jr., 2 João Vicente Vítola 2 Hospital de Clínicas da Universidade Federal do Paraná, 1 Curitiba, PR – Brazil Clínica Quanta Diagnóstico e Terapia, 2 Curitiba, PR – Brazil Mailing Address: Tufi Dippe Jr. • Rua Rocha Pombo, 920 apto. 501. Postal Code 80530-290, Juvevê, Curitiba, PR – Brazil E-mail: tufidippejr@gmail.com , tufidippejr@bol.com.br Manuscript received April 25, 2018, revised manuscript July 16, 2018, accepted July 23, 2018 DOI: 10.5935/abc.20180250 Abstract Background: Obesity is associated with an increased risk of type 2 diabetes mellitus (DM), ischemic heart disease (IHD) and cardiovascular mortality. Several studies have demonstrated the diagnostic and prognostic value of single photon computed tomography-myocardial perfusion scintigraphy (SPECT-MPI) in the evaluation of patients with suspected IHD, including in obese population. Data on clinical risk factors and their association with abnormal myocardial perfusion in obese patients are scarce in the Brazilian population. Objective: To determine the factors associated with abnormal myocardial perfusion in obese individuals without known IHD. Methods: We studied obese patients without known IHD who were referred for evaluation through SPECT-MPI between January 2011 and December 2016. Clinical variables and results of SPECT-MPI were obtained systematically. The distribution of continuous variables was assessed using the Shapiro-Wilk and Shapiro-Francia tests. We used the unpaired Student t test to compare the means of continuous variables with normal distribution and the Chi Square test for binomial variables analysis. A p value < 0.05 was considered statistically significant. The association of the clinical variables for the presence of factors associated with abnormal myocardial perfusion was determined by univariate and multivariate logistic regression analysis, and respective odds ratios (OR) and 95% confidence intervals (CI). Results: The study sample consisted of 5,526 obese patients. Mean body mass index (BMI) of our patients was 33.9 ± 3.7 kg/m², 31% had DM, and myocardial perfusion abnormalities was observed in 23% of the total sample. The factors associatedwith abnormal myocardial perfusion onmultivariate analysis were: age (OR: 1.02, 95%CI 1.01‑1.03, p < 0.001), DM (OR: 1.57, 95% CI 1.31-1.88, p < 0.001), typical angina before the test (OR: 2.45, 95% CI: 1.82-3.31, p < 0.001), need for pharmacologic stress test (OR: 1.61, 95% CI: 1.26-2.07, p < 0.001), less physical effort evaluated in metabolic equivalents (METs) during the exercise treadmill test (OR: 0.89, 95% CI: 0.85-0.94, p < 0.001) and a lower post‑stress left ventricular ejection fraction after stress (LVEF; OR: 0.989, 95% CI: 0.984-0.994, p < 0.001). Conclusion: The factors associated with abnormal myocardial perfusion in obese patients without known IHD were age, DM, presence of typical angina, ventricular dysfunction, and inability to undergo physical stress as clinical variables, in addition to functional capacity during physical stress. (Arq Bras Cardiol. 2019; 112(2):121-128) Keywords: Obesity; Diabetes Mellitus; Myocardial Perfusion Scintigraphy; Coronary Artery Disease. Introduction According to the World Health Organization (WHO), obesity is defined as a body mass index (BMI) ≥ 30 kg/m 2 . 1 In 2016, more than 1.9 billion were overweight, 650 million of them obese. 2 In Brazil, Vigitel 2016, a nationwide telephone survey of protective and risk factors for chronic diseases, sponsored by the Ministry of Health, revealed that 53.8% of Brazilian adults were above ideal body weight. The proportion of obese individuals older than 18 years was 18.9%. 3 Obesity is an independent risk factor for cardiovascular disease. Besides, it increases the risk of traditional risk factors, such as systemic arterial hypertension (SAH), type 2 diabetes mellitus (DM) and dyslipidemias, leading to an increased incidence of ischemic heart disease (IHD), cardiovascular mortality and risk of sudden death. 4-6 Evidence from cohort studies have indicated that obesity is also an independent risk factor for coronary artery disease (CAD). 7-9 Many studies have shown the diagnostic and prognostic value of single-photon emission computed tomography – myocardial perfusion imaging with (SPECT-MPI) in patients with suspected or confirmed IHD, 10-12 including obese patients. 13-15 Nevertheless, information on the predictive role of SPECT-MPI among Brazilian obese subjects are scarce. The aim of this study was to determine factors associated with abnormal SPECT-MPI in a large population of obese subjects without known IHD. 121