Analysis of the Correlation Between Postoperative Temperature Trajectory and Prognosis After Cardiac Surgery: A retrospective analysis of the MIMIC-IV database

Background Hypothermia following cardiac surgery can result in negative postoperative outcomes. The goal of this study was to determine the trend of temperature changes in elderly cardiac surgery patients within three days after surgery, as well as to assess its impact on mortality and poor clinical outcomes. Methods This retrospective cohort study selected elderly patients who underwent cardiac surgery from the MIMIC-IV (Medical Information Mart for Intensive Care IV) database. The Latent Class Trajectory Model (LCTM) was employed to classify heterogeneous patterns of temperature changes in patients following cardiac surgery over a three-day period. Then, disparities in survival across the trajectory groups were analyzed using Kaplan-Meier survival curves. The Cox regression model was used to analyze the relationship between patients' temperature trajectories post-cardiac surgery and their risk of death within one year. A subgroup analysis was performed to identify interaction factors and evaluate the robustness of this finding. Results A total of 1,995 cardiac surgery patients were included in the analysis. All patients were over 65 years of age. Five distinct temperature trajectory groups were identified: Group 1 (293 patients, 14.69%); Group 2 (318 patients, 15.94%); Group 3 (86 patients, 4.31%); Group 4 (892 patients, 44.71%); and Group 5 (406 patients, 20.35%). Kaplan-Meier survival analysis revealed that patients in Group 3 had higher in-hospital and one-year mortality rates than the other groups. Patients in Group 1 had lower in-hospital and one-year mortality rates. Subgroup analysis showed that the one-year mortality rate was higher in Group 3 patients and remained stable across different complication groups. Conclusion Distinguishing different temperature trajectories could help identify patient subgroups at varying risk levels for adverse outcomes after cardiac surgery. This would be a clinically meaningful way to categorize patients. Trial registration : Retrospectively registered.