Autonomic function effects on risk of postoperative complications in gastrointestinal tumors: a retrospective cohort study

Aim To investigate the predictive value of dynamic heart rate variability (HRV) changes during the perioperative period for complications following radical surgery for gastrointestinal tumors. Methods This retrospective cohort study included 231 patients who underwent elective radical surgery for gastrointestinal tumors at the Affiliated Hospital of Nanjing University of Chinese Medicine between May 2022 and September 2025. Based on the occurrence of complications during postoperative hospitalization, they were divided into a complication group (n = 41) and a non-complication group (n = 190). All patients wore a long-term wearable dynamic monitoring device recording dynamic heart rate variability indicators from 24 hours preoperatively to postoperative day 3. Concurrent changes in inflammatory markers were also recorded. Univariate and multivariable logistic regression analyses were used to construct prediction models, and receiver operating characteristic curves were plotted to evaluate their predictive performance. Results The root mean square of successive differences on postoperative day 3 was significantly lower in the complication group than in the non-complication group, while the low-frequency/high-frequency ratio was higher and recovered slowly. Among the inflammatory markers, interleukin-6, white blood cell, and C-reactive protein levels were significantly higher in the complication group. The combined model incorporating heart rate variability trajectory parameters and serum markers demonstrated the highest predictive value (area under the curve [AUC] = 0.832, 95% CI: 0.762–0.902, P < 0.001). Conclusion Dynamic perioperative HRV monitoring can effectively reflect the state of autonomic function under surgical stress. By combining HRV with inflammatory markers, we established the model to identify the association between HRV and the risk of short-term postoperative complications, thereby facilitating the early identification and intervention of high-risk patients.