Objective:

To investigate the dose-response relationship between the triglyceride-glucose (TyG) index and in-hospital major adverse cardiovascular events (MACE) in patients with acute myocardial infarction (AMI), and to examine potential nonlinear associations.

Approach:

• Study Design: Single-center retrospective cohort study involving 1,065 AMI patients who underwent coronary angiography.
• Data Collection: Baseline data collected from electronic medical records; TyG index calculated using the formula: TyG = Ln [triglycerides (mg/dL) × fasting plasma glucose (mg/dL)]/2.
• Outcome Measurement: Primary outcome was in-hospital MACE, defined as a composite of all-cause mortality, acute heart failure, malignant arrhythmia, recurrent myocardial infarction, and cardiogenic shock.
• Statistical Analysis: Multivariable logistic regression and restricted cubic splines used to analyze the association between TyG index groups and MACE.

Key Findings:

• Overall incidence of in-hospital MACE was 21.13%.
• The T2 group had a significantly higher MACE incidence (26.04%) compared to the T1 group (16.76%, p = 0.011).
• In the core model, the T2 group had a 178% increased risk of in-hospital MACE compared to T1 (OR = 2.78, 95% CI: 1.38–5.59, p = 0.004).
• A significant J-shaped relationship was found between the TyG index and MACE risk, with an inflection point at TyG = 9.05.
• For TyG index <9.05, MACE risk did not change significantly (OR = 1.04, 95% CI: 0.62–1.77, P = 0.875); for TyG index ≥9.05, MACE risk increased by 124% (OR = 2.24, 95% CI: 1.26–3.96, P = 0.006).

Interpretation:

The study demonstrates a significant J-shaped nonlinear association between the TyG index and in-hospital MACE risk.

Limitations:

• Single-center study may limit generalizability.
• Retrospective design may introduce bias.
• Potential confounding factors not fully accounted for.

Conclusion:

The findings highlight the importance of considering the nonlinear effect of the TyG index in risk assessment for AMI patients.