Troponin T and Brain Natriuretic Peptide after On-Pump Cardiac Surgery: Prognostic Impact on 12-Month Mortality and Major Cardiac Events After Adjustment for Postoperative Complications
Background—The independent predictive value of troponin T (TNT) after on-pump cardiac surgery was established in several studies. However, adjustment was limited to preoperative risk factors without considering perioperative complications. Data on the prognostic value of postoperative B-type natriuretic peptide (BNP) are scarce. Our aim was to assess independent value of TNT and BNP to predict 12-month outcome after cardiac surgery after adjustment considering preoperative risk estimates and postoperative complications and to report risk stratification gains when considering the EuroSCORE combined with postoperative biomarkers.
Methods and Results—This prospective cohort study included consecutive patients undergoing on-pump cardiac surgery between 2007 and 2010. We evaluated postoperative TNT and BNP, the EuroSCORE, and postoperative complications as predictors of adverse events using Cox regression. The primary endpoint was death or major adverse cardiac events (MACE) within 1 year after surgery. We calculated the net reclassification index (NRI) of TNT and BNP in addition to the EuroSCORE. We enrolled 1559 patients; of whom 176 (11.3%) suffered an event. The adjusted hazard ratio (HR) of TNT >0.8 μg/L was 2.13 (95% CI, 1.47-3.15), of BNP >790 ng/L 2.44 (95% CI, 1.65-3.62). The NRI of the addition of TNT and BNP to the EuroSCORE was 0.276 (95% CI, 0.195-0.348).
Conclusions—Postoperative TNT and BNP are strong predictors of 1-year events after on-pump cardiac surgery independent of preoperative risk factors and postoperative complications. Updating the preoperative EuroSCORE risk with postoperative TNT and BNP after surgery allows for improved prediction of 1-year death or MACE.
- Received November 1, 2013.
- Revision received April 29, 2014.
- Accepted June 16, 2014.