Relationship between postoperative cardiac troponin I levels and outcome of cardiac surgery.
BACKGROUND
Cardiac surgery may be associated with significant perioperative and postoperative morbidity and mortality. Underlying pathology, surgical technique, and postoperative complications may all influence outcome. These factors may be reflected as a rise in postoperative troponin levels. Interpretation of troponin levels in this setting may therefore be complex. This study assessed the prognostic significance of such measurements, taking into account potential confounding variables.


RESULTS
One-thousand three hundred sixty-five patients undergoing cardiac surgery underwent measurement of cardiac troponin I (cTnI) at 2 and 24 hours after surgery. The relationship of these measurements to subsequent mortality was established. After taking into account all other variables, cTnI levels measured at 24 hours were independently predictive of mortality at 30 days (odds ratio [OR] 1.14 per 10 microg/L, 95% confidence interval [CI] 1.05 to 1.24, P=0.002), 1 year (OR 1.10 per 10 microg/L, 95% CI 1.03 to 1.18, P=0.006), and 3 years (OR 1.07 per 10 microg/L, 95% CI 1.00 to 1.15, P=0.04). Cardiac TnI levels in the highest quartile at 24 hours were associated with a particularly poor outcome.


CONCLUSIONS
cTnI levels measured 24 hours after cardiac surgery predict short-, medium-, and long-term mortality and remain independently predictive when adjusted for all other potentially confounding variables, including operation complexity.
Croal
Bernard L
BL
Department of Clinical Biochemistry, University of Aberdeen and Aberdeen Royal Infirmary, Aberdeen, United Kingdom, AB25 2ZD. bernie.croal@nhs.net
Hillis
Graham S
GS
Gibson
Patrick H
PH
Fazal
Mohammed T
MT
El-Shafei
Hussein
H
Gibson
George
G
Jeffrey
Robert R
RR
Buchan
Keith G
KG
West
Douglas
D
Cuthbertson
Brian H
BH
D000368:Aged; D006348:Cardiac Surgical Procedures / Q000401:mortality*; D005260:Female; D006331:Heart Diseases / Q000151:congenital / Q000401:mortality* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality* / Q000601:surgery; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D016037:Single-Blind Method; D016019:Survival Analysis; D019210:Troponin I / Q000097:blood*
D019210:Troponin I