In this study, we examined the relationship between sCD40L and readmission in patients with chronic heart failure, as well as its association with biochemical, demographic, and imaging data. Notably, our study is the first to establish a link between sCD40L levels and readmission in patients with chronic heart failure. Using LASSO analysis, we identified monocytes, creatinine, sCD40L, and hypertension history as independent risk factors for readmission in these patients. Additionally, we developed a nomogram based on sCD40L to predict the probability of readmission for chronic heart failure.
The clinical features of HF patients requiring readmission have been explored, and studies have shown that hemoglobin, blood sodium, SBP, heart rate, blood urea nitrogen, age, troponin, and BNP are risk factors for readmission within 30 days (11). Earlier studies have constructed predictive models for the readmission of HF patients, with age, NYHA, BMI, blood creatinine, and inflammatory markers as key factors, and the area under the curve (AUC) of the model reached 0.739 (95% CI: 0.673–0.800) (12). Studies have also used least absolute shrinkage and selection operator (LASSO) regression to screen for risk factors of readmission within 180 days in HF patients. Age, acute HF, emergency, beta-blocker usage, and blood urea nitrogen were ultimately included in the criteria, and the model's AUC reached 0.75 (95% CI: 0.69–0.81) (13). In our model, the AUC was 0.646 without the use of sCD40L. However, when sCD40L was included as a predictive factor, the AUC reached 0.764, indicating a significant improvement in the prediction.
sCD40L, an inflammatory mediator, is mainly released by activated platelets (6) and is a strong predictor of cardiovascular events. In animal models, previous studies have shown that CD40L promotes platelet aggregation, monocyte recruitment, and exosmosis by promoting the formation of ultra-large von Willebrand factor multipliers, leading to atherosclerosis (14). In a myocardial infarction model, recombinant sCD40L can specifically bind alphaIIbbeta3 and activated platelets, inducing platelet diffusion (15). Some studies have explored the relationship between cardiovascular disease and sCD40L levels. In a study by Christopher, an increase in sCD40L levels in acute coronary syndrome leads to an increased risk of recurrent myocardial infarction and death (16). Hamdi also obtained similar results, indicating that higher levels of sCD40L were associated with the 1-year all-cause mortality rate of ST-segment elevation myocardial infection in patients receiving primary percutaneous coronary intervention (17). Recent studies have shown that changes in the c allele of CD40's single nucleotide polymorphism can cause a pro-inflammatory phenotype in endothelial cells (18). In summary, several studies have confirmed that sCD40L is closely associated with the risk of cardiovascular diseases. Therefore, further research is required to confirm the relationship between sCD40L levels and cardiovascular disease prognosis.
We also conducted a correlation analysis between sCD40L levels and various parameters. Our findings revealed a positive correlation between sCD40L and males, which is consistent with existing literature. This may be due to the higher smoking rate among men, as smoking is a key factor leading to inflammatory reactions(19, 20). Additionally, we observed a positive correlation between sCD40L and some inflammatory markers and harmful metabolites such as hsCRP, uric acid, and LDL-C, which is in line with previous reports. However, we found a negative correlation between sCD40L levels and FBG, HBA1C, diabetes history. This could be because we did not collect information on the medication of patients for controlling blood sugar levels. Moreover, we noted a positive correlation between sCD40L levels and EF/FS. These are indicators used to diagnose heart failure and reflect its severity.Taken together, our results suggest that high sCD40L levels are associated with readmission risk in patients with chronic heart failure.
Finally, we constructed a nomogram based on sCD40L to predict the risk of readmission within 180 days for patients with chronic heart failure. Our model has demonstrated good accuracy and can provide clinicians with valuable insights to develop a more comprehensive plan for managing heart failure patients.
Our study had some limitations. First, sCD40L levels were measured from the blood samples collected from patients 2–3 days after admission. During sample processing, there may be degradation of sCD40L, which may cause errors in the experimental results. Second, although this was a prospective cohort study, there was no causal relationship between sCD40L levels in chronic HF patients and the time of readmission. Finally, owing to the limitations of the study, our sample size was relatively small, and we need to expand the sample size further to verify the accuracy of the model.