A postoperative dynamic nomogram for predicting myocardial injury after noncardiac surgery in high-risk patients undergoing laparoscopic colorectal cancer resection.

BACKGROUND

Myocardial injury after noncardiac surgery (MINS) is closely associated with perioperative cardiovascular events and is a critical complication leading to poor prognosis. This study aimed to develop a nomogram model to predict the risk of MINS in high-risk patients undergoing colorectal cancer surgery, which can be applied immediately after surgery to guide postoperative troponin monitoring and individualized intervention.

METHODS

This study retrospectively included 358 patients at high cardiovascular risk who underwent laparoscopic colorectal cancer surgery from August 2021 to January 2023. They were assigned randomly to training and validation cohorts in a 7:3 ratio. After univariate analysis and multicollinearity assessment, multivariable logistic regression identified independent predictors associated with MINS in the training cohort, and nomogram prediction models were constructed. The nomogram model's discrimination, calibration, and clinical validity in the training and validation cohorts were evaluated and validated.

RESULTS

Age, preoperative hemoglobin, preoperative high-sensitivity troponin T (hs‑cTnT), and the Surgical Apgar Score (SAS) were identified as independent predictors. The AUC (C‑index) of the nomogram constructed from these four predictors was 0.884 (95% CI: 0.831-0.937) and 0.853 (95% CI: 0.729-0.977) in the training and validation cohorts, respectively. Decision curve analysis indicated favorable clinical utility, with a positive net benefit across a wide range of threshold probabilities including the recommended 20% risk threshold.

CONCLUSION

A postoperative dynamic nomogram based on preoperative and intraoperative variables provides a simple, practical tool for predicting MINS risk in high-risk patients undergoing colorectal cancer surgery. The model showed favorable discriminative ability and calibration upon internal validation, but prospective external validation is needed before clinical implementation.

TRIAL REGISTRATION: The study was registered with the Chinese Clinical Trial Registry (ChiCTR2200065961, 20/11/2022).