Objective:

To evaluate the clinical value of perioperative global longitudinal strain (GLS) derived from transesophageal two-dimensional speckle-tracking echocardiography (2D-STI) in predicting biomarker-defined postoperative myocardial injury and early cardiac functional alterations in patients undergoing off-pump coronary artery bypass grafting (OPCABG).

Approach:

• Study Design: 113 patients scheduled for OPCABG were enrolled. GLS was measured at three time points: after anesthesia induction (T0), after graft reperfusion and protamine neutralization (T1), and 1.5 hours after reperfusion (T2).
• Data Collection: Transit-time flow measurement (TTFM) parameters and biomarkers (CK-MB, hs-cTnI, BNP, LVEF) were assessed perioperatively.
• Statistical Analysis: Spearman correlation, repeated-measures ANOVA, multivariable logistic regression, and ROC analyses were performed.

Key Findings:

• 47 patients were classified as high risk and 66 as low risk based on postoperative hs-cTnI thresholds.
• High-risk group had significantly lower GLS values at T0, T1, and T2 compared to low-risk group.
• GLS at all time points was negatively correlated with 48-hour peak CK-MB, hs-cTnI, and BNP.
• GLS at T0, T1, and T2 were independently associated with biomarker-defined postoperative myocardial injury.
• Δ1 and Δ2 values were lower in the high-risk group compared to the low-risk group.
• ROC analysis showed predictive value for T0 GLS, T2 GLS, and Δ2 with AUCs of 0.885, 0.884, and 0.840, respectively.

Interpretation:

Perioperative GLS derived from transesophageal 2D-STI is associated with hs-cTnI elevation-defined postoperative myocardial injury and early cardiac functional alterations in patients undergoing OPCABG.

Limitations:

• Study conducted at a single center, which may limit generalizability.
• Sample size may not be sufficient to detect all potential associations.

Conclusion:

GLS provides complementary information on myocardial function.