title: Cystatin C as a predictive marker of renal dysfunction and mid-term outcomes following off-pump coronary artery bypass grafting.
abstract: OBJECTIVE
  To determine whether plasma cystatin C and creatinine levels after isolated off-pump coronary artery bypass grafting (OPCAB) are predictive of postoperative renal dysfunction and clinical outcomes.
  
  
  METHODS
  Between January 2008 and December 2013, 1033 who underwent isolated OPCAB were recruited. The patients were divided into three groups according to the preoperative level of cystatin C: low (0.83 mg/L>), mid (0.83-1.13 mg/L) and high (1.13 mg/L<). The endpoints of all-cause mortality and major adverse cerebrovascular and cardiovascular events were compared among three groups using the Kaplan-Meier method. The predictive power of cystatin C was compared with creatinine using receiver operating curves.
  
  
  RESULTS
  Follow-up was complete in all of the included patients at a mean of 2.9±1.5 years. Within the follow-up period, 9 early (30-day mortality) and 46 late deaths occurred. The 30-day mortality was zero, four (44%), and five (56%) cases in low, mid and high groups, respectively (p=0.03). The cut-off value of cystatin C for renal dysfunction prediction was approximately 1.04 (mg/L, p<0.001), and cystatin C showed greater predictive power than creatinine for renal dysfunction (area under the curve=0.73 vs 0.65; p=0.01). One-year and five-year overall survival in low, mid and high groups were 99.2%, 98.9% and 94.3%, and 97.9%, 97.3% and 86.3%, respectively (low vs high, p=0.01).
  
  
  CONCLUSIONS
  Cystatin C is a stronger predictor of postoperative renal dysfunction than serum creatinine, and its level is directly correlated with mid-term OPCAB adverse results.
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Severance Cardiovascular Hospital, Yonsei University, College of Medicine, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Severance Cardiovascular Hospital, Yonsei University, College of Medicine, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Young-Nam
authors.initials: YN
authors.lastname: Youn
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Severance Cardiovascular Hospital, Yonsei University, College of Medicine, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Hyun Chel
authors.initials: HC
authors.lastname: Choo
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Severance Cardiovascular Hospital, Yonsei University, College of Medicine, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Sak
authors.initials: S
authors.lastname: Lee
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Severance Cardiovascular Hospital, Yonsei University, College of Medicine, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Kyung-Jong
authors.initials: KJ
authors.lastname: Yoo
mesh_terms: D000368:Aged; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects* / Q000401:mortality; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000097:blood*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007668:Kidney / Q000503:physiopathology; D007674:Kidney Diseases / Q000097:blood / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D003404:Creatinine