Using the SYNTAX score to predict myocardial injury early after on-pump coronary artery bypass surgery: 76 a single-centre experience analysis

Introduction
Marked isolated elevation of cardiac biomarkers (CK-MB, cardiac troponin I, heart-type fatty acid binding protein, hFABP) within 48 hours after coronary artery bypass surgery (CABG), even in the absence of electrocardiographic/angiographic evidence of myocardial infarction (MI), indicates prognostically significant cardiac procedural myocardial injury. There are no data exploring the relationship between the complexity of coronary atherosclerotic burden and early post-CABG myocardial injury.

Aim
To analyse correlations and predictive strength of the SYNTAX score (SS) for early myocardial injury after on-pump CABG.

Material and methods
One hundred and twenty consecutive patients undergoing CABG were included in the analysis. We obtained data on demographics, medical history, cardiovascular risk factors and echocardiography. Cardiac biomarkers were assessed at 6 hours after CABG. Multivariate linear regression analysis was performed to evaluate independent variables correlated with cardiac biomarkers.

Results
The most significant predictor for myocardial injury was SS, strongly correlated with the rise of all cardiac biomarkers (p < 0.001). Hypertension and creatinine clearance were associated with cTnI and hFABP. Diabetes was corelated with hFABP. In a multivariate analysis including all significant predictors, SS remained an independent predictor for myocardial injury, strongly associated with hFABP (p < 0.001, OR = 5.79, 95% CI: 3.59–7.98), cTnI (p < 0.001, OR = 6.49, 95% CI: 4.78–8.20), but not with CK-MB (95% CI: 0.61–1.07).

Conclusions
Defining myocardial injury as elevation of cardiac biomarkers between normal values and the cut-off for MI has a tremendous clinical significance as patients maintain high negative prognostic rates. SS could be used to predict post-operative rise of cardiac biomarkers, the correlation between SS and myocardial injury being very solid.