IJCS | Volume 31, Nº3, May/ June 2018

219 Cardoso et al. Correlation between coronary lesions and troponin International Journal of Cardiovascular Sciences. 2018;31(3)218-225 Original Article shows higher analytical sensitivity enabling precise quantification of low troponin concentrations. Therefore, hsTn can exclude AMI earlier than other less sensitive, conventional markers. However, its indiscriminate use may lead to false positive results while contributing with few additional cases of ischemia. 6 Prognostic evaluation of ACSs includes clinical, laboratory and anatomical criteria. One of the anatomical criteria is the SYNTAX score, which has been established to evaluate the complexity of coronary lesions diagnosed by coronary angiography. SYNTAX score is a comprehensive angiographic rating system derived from anatomical features and coronary lesion. 7 Several studies have consistently demonstrated a positive relationship between increased hsTn and the prognosis of patients with ACSs. 8 Nevertheless, few studies have evaluated the relationship between hsTn and the complexity of angiographic coronary lesions. 9 In light of this, the aim of the present study was to correlate hsTn levels with the complexity of coronary lesions according to the SYNTAX score in patients admitted for ACSs. Considering the prognostic value of this biomarker, we will also compare this hsTn levels with previously validated risk scores, the GRACE and TIMI scores. Methods This was a retrospective, cross-sectional, analytical study using convenience sampling, and collection of secondary data from medical records. From January to June 2013, 211 patients with suspicion of ACS (AMI and unstable angina) were admitted to the emergency department of Maria Aparecida Pedrossian University Hospital. Among these patients, 174 had the diagnostic confirmed and underwent coronary angiography during hospitalization, and hence considered eligible for the study. The myocardial necrosis markers and respective reference values used in this institution are: hsTn > 14 pg/mL and CKMB (mass) > 3.8 ng/mL in women and 6.7 ng/mL in men. Patients’ highest troponin levels were considered for the analysis of correlation between troponin and lesion complexity. For the diagnosis of unstable angina, we considered: pain or discomfort in the chest, epigastrium, mandible, shoulder, back or upper limbs, with onset at rest, and of early or progressive onset. 10 Anatomical complexity of coronary lesions was classified by the SYNTAX score, using a validated calculator available at http://www.syntaxscore.com. The score evaluates the number, localization, extension and morphology of lesions. Patients with scores lower than 22 were considered at low risk, patients with scores from23 to 32 were considered at moderate risk, and those with scores higher than 32 were considered at high risk. All tests were revised and the score rated by the same experienced hemodynamic technician. TIMI and GRACE clinical scores were used for risk stratification of the included patients. GRACE score was calculated using the electronic calculator available at http://www.outcomes-umassmed.org/ GRACE/ acs_risk/acs_risk_content.html. Patients with a score lower than 109 were considered at low risk; patients with a score between 109 and 140 were considered at intermediate risk, and those with scores higher than 140 were considered at high cardiovascular risk. Patients were considered diabetic if they met one of the following criteria, according to the Brazilian Diabetes Society Guidelines: 11 previous diagnosis of the disease and use of glucose-lowering agents; patients without a previous diagnosis of the disease with fasting glucose levels equal to or greater than 126 mg/dL, plasma glucose level after a 75 g glucose load equal to or greater than 200 mg/dL, casual glucose level equal to or greater than 200 mg/dL associated with classical symptoms (polyuria, polydipsia, unexplained weight loss), or glycated hemoglobin levels higher than 6.5%. 11 Patients who reported smoking a cigarette in the year prior to the study, and those who had quit smoking less than 30 days were considered smokers. Inclusion criteria were: patients older than 18 years with a confirmed diagnosis of ACS according to the Third Universal Definition of Myocardial Infarction. 3 Patients who had not undergone a coronary angiography during hospitalization were excluded from the study. The study was approved by the research ethics committee of the Federal University of Mato Grosso do Sul (approval number 51783415.1.0000.0021). Statistical analysis Linear correlations of hsTn levels with TIMI, GRACE and SYNTAX scores were assessed by the nonparametric Spearman correlation coefficient, since the data did not pass the Shapiro-Wilk test for normality. The other results were described using descriptive statistics or in tables