Myocardial injury after off-pump coronary artery bypass grafting operation

Eur J Cardiothorac Surg. 2007 Sep;32(3):481-7. doi: 10.1016/j.ejcts.2007.06.015. Epub 2007 Jul 23.

Abstract

Objective: Perioperative myocardial ischemia is less pronounced in off-pump coronary artery bypass (OPCAB) compared to on-pump coronary artery bypass; however, the threshold over which the postoperative release of cardiac troponin I (cTnI) release and creatine kinase-MB (CK-MB) after OPCAB should be considered clinically relevant is unknown. The study was designated to evaluate if perioperative myocardial damage, measured by means of postoperative release of cTnI and CK-MB, has an influence on short- and mid-term outcome after OPCAB operations.

Methods: Two hundred and sixty-one unselected patients undergoing OPCAB had cTnI and CK-MB measured preoperatively and nine times postoperatively. Postoperative peak values were evaluated and the 80th percentiles were used to segregate the population into two groups for each marker. The following cut-offs were used: 7.1 ng/dl for cTnI peak and 36.3 ng/dl for CK-MB peak.

Results: Patients with cTnI>7.1 ng/ml (n=51) and CK-MB>36.3 ng/ml (n=48) had a longer mechanical ventilation and ICU length of stay. Nevertheless, hospital mortality did not differ between groups. Survival after 3 years was 92.8+/-2.3% and 81.8+/-6.2 for patients with postoperative cTnI peak<or=7.1 ng/ml and >7.1 ng/ml, respectively (p=0.003). It was 93+/-2.2% and 80+/-6.8% for patients with CK-MB<or=36.3 ng/ml and >36.3 ng/ml, respectively (p=0.005). Adjusted hazard ratios for mid-term mortality were HR 2.7 (CI 1-7.6), p=0.05 for cTnI>7.1 ng/dl and HR 3.1 (CI 1-9.1), p=0.04 for CK-MB>36.3 ng/ml.

Conclusion: Perioperative myocardial damage should not be considered an innocuous event following OPCAB operations since the survival rate over 3 years is significantly worse in patients with the highest postoperative peak release of cTnI and CK-MB.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biomarkers / blood
  • Coronary Artery Bypass, Off-Pump / adverse effects*
  • Coronary Artery Bypass, Off-Pump / mortality
  • Creatine Kinase, MB Form / blood*
  • Female
  • Hospital Mortality
  • Humans
  • Male
  • Myocardial Ischemia / blood
  • Myocardial Ischemia / etiology*
  • Postoperative Complications / etiology*
  • Postoperative Complications / mortality
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Survival Analysis
  • Troponin I / blood*

Substances

  • Biomarkers
  • Troponin I
  • Creatine Kinase, MB Form