ACA App
Annals of Cardiac Anaesthesia Annals of Cardiac Anaesthesia Annals of Cardiac Anaesthesia
Home | About us | Editorial Board | Search | Ahead of print | Current Issue | Archives | Submission | Subscribe | Advertise | Contact | Login 
Users online: 778 Small font size Default font size Increase font size Print this article Email this article Bookmark this page
 


 

 
     
    Advanced search
 

 
 
     
  
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
    Email Alert *
    Add to My List *
* Registration required (free)  


    References
    Article Figures
    Article Tables

 Article Access Statistics
    Viewed2992    
    Printed75    
    Emailed1    
    PDF Downloaded326    
    Comments [Add]    

Recommend this journal

 


 
LETTER TO EDITOR Table of Contents   
Year : 2009  |  Volume : 12  |  Issue : 1  |  Page : 86-88
The value of postoperative troponin levels in predicting long-term mortality after coronary artery bypass surgery


1 Department of Anesthesiology, University of Ioannina, School of Medicine, 45110 Loannina, Greece
2 Department of Internal Medicine, University of Ioannina, School of Medicine, 45110 Loannina, Greece
3 Department of Cardiology, University of Ioannina, School of Medicine, 45110 Loannina, Greece
4 Department of Cardiothoracic Surgery, University of Ioannina, School of Medicine, 45110 Loannina, Greece

Click here for correspondence address and email
 

How to cite this article:
Tzimas P, Milionis HJ, Arnaoutoglou H, Kalantzi K, Karfis E, Korantzopoulos P, Pappas K, Drossos G, Papadopoulos G. The value of postoperative troponin levels in predicting long-term mortality after coronary artery bypass surgery. Ann Card Anaesth 2009;12:86-8

How to cite this URL:
Tzimas P, Milionis HJ, Arnaoutoglou H, Kalantzi K, Karfis E, Korantzopoulos P, Pappas K, Drossos G, Papadopoulos G. The value of postoperative troponin levels in predicting long-term mortality after coronary artery bypass surgery. Ann Card Anaesth [serial online] 2009 [cited 2019 Nov 22];12:86-8. Available from: http://www.annals.in/text.asp?2009/12/1/86/45023


The Editor,

Despite advances in techniques and devices, postoperative complications after coronary artery bypass grafting (CABG) surgery represent a significant problem that adversely affect both short- and long-term prognosis. There seems to be a continuous need for the establishment of markers with sufficient predictive value, especially with regard to long-term prognosis. Several risk scores such as the commonly used EuroSCORE have been developed aiming at the prediction of perioperative mortality. [1] However, these scores are based only on the assessment of preoperative clinical variables, not taking into account perioperative and postoperative complications. Thus, there is an increasing interest for the development of novel easily applied markers that have the potential to enhance our predictive ability.

Biochemical markers of myocardial injury can be easily determined during the early postoperative period. Postoperative troponin elevation is a common phenomenon with several potential mechanisms that often leads to diagnostic confusion. Regardless of the underlying cause, it reflects myocardial damage. Cardiac troponin I (cTnI) represents a sensitive and specific marker of myocardial damage in various conditions including the postoperative setting. [2] However, its value in predicting long-term mortality after CABG, the determination of the threshold level, and the best timing for the assessment have not been well-studied, while inconsistent results have been published in the literature. [3],[4],[5],[6],[7],[8] We investigated the value and the threshold level of postoperative cTnI in predicting long-term mortality after CABG surgery.

Forty-one consecutive patients who underwent elective CABG were prospectively studied. Exclusion criteria included emergency surgery, re-operative procedures, concomitant valve repair or replacement, and preoperative chronic kidney disease (creatinine clearance <60 ml/min). cTnI levels were measured in blood samples preoperatively upon admission to the intensive care unit and at 12, 24, 36 and 48 h after surgery as well as daily on postoperative days 3-7. However, after checking the peak concentration and the diagnostic utility (in accordance with previous studies), we decided to further examine the value cTnI levels after 24 h in predicting mortality 3 years after the operation. cTnI concentrations were measured by IMMULITE 2000 Troponin I, a solid-phase, two-site chemiluminescent immunometric assay (Diagnostic Products Corporation, Corporate Offices, LA, USA). The detection threshold for the assay is 0.2 ng/ml. All patients gave informed consent and the study protocol was approved by the institutional ethics committee.

Data were expressed as mean standard deviation (SD) or mean standard error of mean (SEM) as appropriate. Comparisons of continuous variables were performed by Student's t-test for normally distributed variables and Mann-Whitney U test for non-normally distributed variables, while chi-square tests were used for categorical variables. The diagnostic utility of cTnI was examined with receiver operating characteristic (ROC) curves. Significance was set at an alpha level of 0.05. All analyses were carried out with SPSS 11.0 statistical package for Windows (SPSS Inc, Chicago, Ill).

The patient group consisted of 33 men and 8 women with a mean age of 64 9.2 years. All patients were successfully subjected to CABG surgery and discharged from the hospital alive and in good clinical condition. However, after a period of 3 years, 5/41 (12.2%) patients had been died. All deaths reported to be of cardiac origin. The clinical characteristics of the patients during the perioperative period are presented in [Table 1]. Patients who died had significantly higher EuroSCORE values at the baseline assessment, they more frequently required intra-aortic balloon pump (IABP) support, and hospitalized for longer periods after the operation [Table 1]. There was also a trend towards lower baseline left ventricular ejection fraction in patients who subsequently died [Table 1]. ROC curve analysis showed that cTnI 24 h postoperatively is of important value in predicting death during the long-term follow-up ([Figure 1], AUC: 0.834, P = 0.018). A threshold value of 13.4 ng/ml was highly associated with long-term mortality with a sensitivity of 100% and a specificity of 76%. The clinical characteristics of the patients when divided into two groups according to the threshold value of cTnI are presented in [Table 2]. Patients at higher risk according to cTnI levels (≥13 ng/ml) had more frequently left main disease needed more frequently IABP support and were hospitalized in the intensive care unit for longer periods [Table 2].

According to our findings, troponin levels after CABG surgery could be used to predict increased long-term risk for death. In line with previous studies, our study supports the value of postoperative cTnI in predicting long-term mortality, while it reinforces the view that a cut-off value in the range of 13 ng/ml measured 24 h after surgery is possibly the most acceptable threshold level. [3] The value of cTnI measurement may be additive to other well-established clinical tools such as the EuroSCORE. Obtaining these measurements in the peri- and post-operative period seems to be of clinical significance in identifying high-risk CABG patients. More studies are needed to further clarify the exact role of postoperative troponin measurement in mortality prediction.

 
   References Top

1.Nashef SA, Roques F, Michel P, Gauducheau E, Lemeshow S, Salamon R. European system for cardiac operative risk evaluation (EuroSCORE). Eur J Cardiothorac Surg 1999;16:9-13.  Back to cited text no. 1  [PUBMED]  [FULLTEXT]
2.Jaffe AS, Ravkilde J, Roberts R, Naslund U, Apple FS, Galvani M, et al . It's time for a change to a troponin standard. Circulation 2000;102:1216-20.  Back to cited text no. 2  [PUBMED]  [FULLTEXT]
3.Fellahi JL, Gue X, Richomme X, Monier E, Guillou L, Riou B. Short and long-term prognostic value of postoperative cardiac troponin I concentration in patients undergoing coronary artery bypass grafting. Anesthesiology 2003;99:270-4.  Back to cited text no. 3    
4.Onorati F, De Feo M, Mastroroberto P, Cristodoro L, Pezzo F, Renzulli A, et al . Determinants and prognosis of myocardial damage after coronary artery bypass grafting. Ann Thorac Surg 2005;79:837-45.   Back to cited text no. 4  [PUBMED]  [FULLTEXT]
5.Croal BL, Hillis GS, Gibson PH, Fazal MT, El-Shafei H, Gibson G, et al . Relationship between postoperative cardiac troponin I levels and outcome of cardiac surgery. Circulation 2006;114:1468-75.  Back to cited text no. 5  [PUBMED]  [FULLTEXT]
6.Riedel BJ, Grattan A, Martin CB, Gal J, Shaw AD, Royston D. Long-term outcome of patients with perioperative myocardial infarction as diagnosed by troponin I after routine surgical coronary artery revascularization. J Cardiothorac Vasc Anesth 2006;20:781-7.  Back to cited text no. 6  [PUBMED]  [FULLTEXT]
7.Fellahi JL, Hedoire F, Le Manach Y, Monier E, Guillou L, Riou B. Determination of the threshold of cardiac troponin I associated with an adverse postoperative outcome after cardiac surgery: A comparative study between coronary artery bypass graft, valve, and combined cardiac surgery. Crit Care 2007;11:R106.  Back to cited text no. 7  [PUBMED]  [FULLTEXT]
8.Adabag AS, Rector T, Mithani S, Harmala J, Ward HB, Kelly RF, et al . Prognostic significance of elevated cardiac troponin I after heart surgery. Ann Thorac Surg 2007;83:1744-50.  Back to cited text no. 8  [PUBMED]  [FULLTEXT]

Top
Correspondence Address:
Panagiotis Korantzopoulos
Department of Cardiology, University of Ioannina, Medical School, 45110 Loannina
Greece
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0971-9784.45023

Clinical trial registration None

Rights and Permissions


    Figures

  [Figure 1]
 
 
    Tables

  [Table 1], [Table 2]



 

Top