IJCS | Volume 31, Nº3, May/ June 2018

DOI: 10.5935/2359-4802.20180010 290 REVIEW ARTICLE International Journal of Cardiovascular Sciences. 2018;31(3)290-307 Mailing Address: Caroline Pereira Domingueti Universidade Federal de São João Del-Rei - Campus Centro Oeste Dona Lindu - Rua Sebastião Gonçalves Coelho, 400. Postal Code: 35501-296, Chanadour, Divinópolis, MG - Brazil. E-mail: caroldomingueti@ufsj.edu.br , caroldomingueti@yahoo.com.br Clinical Usefulness of Cystatin C to Assess the Prognosis of Acute Coronary Syndromes: A Systematic Review and Meta-Analysis Karine Farnese Costa Martucheli and Caroline Pereira Domingueti Universidade Federal de São João Del-Rei, São João Del-Rei, MG - Brazil Manuscript received July 06, 2017, revised manuscript September 27, 2017, accepted October 16, 2017. Acute Coronary Syndrome / Physiopathology; Cystatin C; Prognosis, Biomarkers. Keywords Abstract Cystatin C is used as a marker of renal function and has been shown to be promising for evaluating the prognosis of acute coronary syndromes (ACSs). To evaluate the prognostic value of cystatin C in patients with ACSs. The articles were searched using PubMed, Web of Science and Scielo databases. Observational cohort studies that evaluated the association between increased cystatin C and the development of cardiovascular events and mortality in patients with ACSs were included. Only studies that evaluated similar outcomes, studies that compared the highest with the lowest quartiles of cystatin C, and studies that performed multivariate analysis that included glomerular filtration rate or serum creatinine, were included in the meta-analysis. Methodological quality of the articles was assessed using the Newcastle- Ottawa Scale questionnaire for cohort studies. After applying the eligibility criteria, 17 studies were included in the systematic review. All included studies reported a significant association between higher levels of cystatin C and outcomes. The meta-analysis demonstrated that elevated levels of cystatin C are associated with increased risk of cardiovascular mortality or non-fatal myocardial infarction in patients with ACSs, and such association is independent of renal function [OR = 1.65 (1.464 – 1.861), p < 0.001]. Among the studies included, 4 have good quality and 13 have excellent methodological quality.The systematic review and meta-analysis demonstrated that there is a significant association between increased cystatin C levels and the development of cardiovascular events and mortality in patients with ACSs. Introduction CystatinC is aproteinbelonging to cystatin superfamily of human cysteine protease inhibitors, which is composed of 12 proteins. 1 It is produced at a constant rate by nucleated cells. Due to its lowmolecular weight (13-kDa) and basic isoelectric point, cystatin C is removed from the bloodstreamby glomerular filtration, reabsorbed and catabolized by tubular epithelial cells. 2 Serum cystatin C has been used as a marker of renal function, and suggested as a better endogenous marker of glomerular filtration rate (GFR) compared with serum creatinine. 2,3 The protein is able to detect small reductions in GFR, enabling the early diagnosis of renal dysfunction. 4 Some studies have demonstrated that increased levels of cystatin C in patients with acute coronary syndrome (ACS) are associated with increased risk for cardiovascular events, cardiovascular death and overall mortality, indicating that cystatin C is a promising prognostic marker of ACSs. 5-7 However, due to lack of scientific evidence of its prognostic value, cystatin C has not been used in clinical practice. Few systematic reviews 8 or meta-analysis 9-11 have been performed on the theme, and none of them has included exclusively ACS patients. Therefore, it is of great importance the development of a systematic review and a meta-analysis on this subject in order to compile and analyze the results of currently available