Prediction Model for MINS After Major Hepatobiliary Surgery

Study Design and Methodology: The study consists of four consecutive phases aimed at constructing a robust and interpretable prediction model for MINS.

1. Multi-center Cohort Standardization: Based on clinical data from multiple participating centers, the investigators will establish a standardized structural dataset. Strict inclusion and exclusion criteria will be applied. The process involves rigorous data cleaning and normalization to harmonize demographics, surgical operation details, and perioperative hemodynamic parameters across different centers, laying the foundation for model construction.
2. Nested Modeling and Performance Evaluation: A nested modeling strategy will be employed to assess the incremental predictive value of specific surgical and biological variables:

Model A (Baseline): Constructed using standard baseline variables such as the Revised Cardiac Risk Index (RCRI).

Model B (+Surgical Technique): Incorporates hepatic inflow occlusion strategies, specifically comparing SPVO (Selective Pringle Vascular Occlusion) vs. Pringle maneuver, along with occlusion duration and frequency.

Model C (Full Model): Further incorporates MINS-related biomarkers.

Model performance will be comprehensively evaluated using:

Discrimination: Area Under the Receiver Operating Characteristic Curve (AUC).

Calibration: Calibration plots.

Clinical Utility: Net Reclassification Improvement (NRI) and Decision Curve Analysis (DCA) to assess the improvement in risk stratification and clinical net benefit after adding new variables.
3. Model Interpretability Analysis: To enhance the transparency of the model ("White-box" approach), SHAP (SHapley Additive exPlanations) values or similar methods will be utilized. This will quantify and visualize the specific contribution (weight) of key variables, such as SPVO usage, to the individual risk prediction, aligning the statistical results with clinical medical reasoning.
4. External Validation: The final model will undergo validation using an independent external clinical cohort. This step aims to test the stability and generalizability of the model across different center data, defining its applicable scope in real-world clinical scenarios.

• Major Hepatobiliary Surgery (Procedure): Patients undergo standard major hepatobiliary surgery (e.g., hepatectomy). The specific surgical strategy, including the method of hepatic inflow occlusion (e.g., Pringle maneuver or SPVO), is determined by the attending surgeon based on routine clinical practice and patient condition, not by the study protocol.

Primary outcomes

• The area under the receiver operating characteristic curve (AUC) of predictive model [Within 3 days after surgery]: The area under the receiver operating characteristic curve (AUC) for predicting myocardial injury after noncardiac surgery (MINS) in patients undergoing major hepatobiliary surgery

Secondary outcomes

• Model calibration [Within 3 days after surgery]: assessed by calibration curve / Hosmer-Lemeshow test
• Decision curve analysis (DCA)-derived clinical net benefit [Within 3 days after surgery]
• Model stability and generalizability in the external validation cohort [Within 3 days after surgeries]
• Contribution weight of key variables (SPVO, biomarkers) analyzed via SHAP [Within 3 days after surgeires]

Sex: All, ages: 18 Years to 85 Years

Inclusion Criteria:

Adults (18-85 yr, ASA physical status II-III) undergoing major hepatobiliary surgery were enrolled. Major surgery was defined as duration ≥ 3 h involving hepatectomy (≥ 3 segments) or biliary reconstruction necessitating ICU admission. Eligibility required paired perioperative high-sensitivity cardiac troponin T (hs-cTnT) data and comprehensive documentation of surgical covariates, including surgical approach (laparoscopic vs. open), resection nature (anatomic vs. non-anatomic), number of resected segments, tumor characteristics (size and location), and presence of cirrhosis.

Exclusion Criteria:

(1) preoperative acute myocardial infarction, unstable angina, heart failure, or chronic kidney disease (estimated glomerular filtration rate < 60 ml/ (min · 1.73 m2); (2) undocumented inflow occlusion strategy; or (3) non-imputable missing covariates.

• Zhifeng Gao, MD, Principal investigator, Beijing Tsinghua Changgeng Hospital