IJCS | Volume 31, Nº3, May/ June 2018

223 Figure 3 - Scatter plot showing a significant weak, positive linear correlation between high-sensitivity troponin levels and GRACE score. Each plot represents one patient. Dashed line represents the linear regression. P-value of Spearman rank correlation test, and “r” is the linear correlation coefficient. High-sensitivity troponin (pg/mL) p = 0.001 r = 0.261 GRACE score Cardoso et al. Correlation between coronary lesions and troponin International Journal of Cardiovascular Sciences. 2018;31(3)218-225 Original Article high sensitivity of the troponin used in our study, and the possibility of increased hsTn levels in conditions other than ACSs, such as sepsis, stroke, among others. Although previous studies on the subject have compared troponin levels with the severity of coronary lesions, neither hsTn nor the SYNTAX score for evaluation of the severity of these lesions was used in these studies. One example was the Brazilian study by Faria RC. 13 The author compared the levels of troponin I with the severity of coronary lesions, which was measured by characteristics of the lesions in cardiac catheterization or changes in coronary circulation. In this study, although the author found no statistically significant correlation between increased troponin I levels and lesion severity or coronary circulation, the protein levels were correlated with a higher number of obstructive lesions and the presence of thrombus. 13 In addition, in our study, hsTn levels were correlated with GRACE and TIMI clinical prognostic scores. The linear correlation between these parameters, despite weak, suggests a worse prognosis of patients with higher levels of this biomarker. Median GRACE and TIMI scores (121 and 3, respectively) found in our population indicated an intermediate risk in these patients, whose hsTn levels were 4 times the upper limit of normal range (cut-off point: 14 pg/dL). In a similar study by Biener et al., 14 rising and falling changes of hsTn at admission were correlated with GRACE risk score, aiming to evaluate whether these changes would improve the prognostic performance of the score. The authors suggested that a GRACE score ≥ 140 points and hsTn admission values above the 99th percentile are reliable indicators of adverse cardiovascular events in hospitalized patients with suspicious of ACS. Nevertheless, neither rising nor falling hsTn kinetic changes seemed to add prognostic information. 14 Although we did not evaluate the presence of kinetic changes or the possibility of future cardiovascular events, we found slightly increased hsTn levels associated with intermediate GRACE score values. The linear relationship, despite weak, may also suggest a worse prognosis in these patients. With respect to TIMI score, we also found some studies that directly compared it with troponin. Gomes et al., 15 for example, evaluated the relative contribution of hsTn to the final risk classification of patients with ACS without ST-segment elevation, previously evaluated by the TIMI score, and found that hsTn contributed to their