#2992 Modifiable factors involved in sudden death risk in a large population on chronic hemodialysis

Abstract Background and Aims End-stage renal disease patients receiving hemodialysis (HD) have an exceedingly high risk of cardiac sudden death, that may occur between treatments (extra dialytic sudden death, SD) or during the dialysis session (intradialytic SD). Even considering that these two entities may represent different clinical situations, the identification of potentially modifiable risk factors for SD in HD patients seems fundamental for the implementation of strategies to reduce the incidence of such events. Some HD registry-based observational studies have suggested some factors eventually implicated in SD risk, but the results are conflicting and further clarification is needed. The aim of our study was to evaluate the variables associated with the risk of SD in a large population of HD patients. Method We performed a retrospective cohort study using data from an international HD provider database. All patients in maintenance HD during 2024 were included. Deaths occurring during the year were gathered and divided in two groups: Group 1) non-sudden deaths; Group 2) sudden deaths, defined as unexpected, natural deaths occurring within 1 hour of symptom onset if witnessed or, if unwitnessed, within 24 hours of having been last seen alive and symptom-free. The last demographic, clinical and analytical data available before the event were collected and the two groups compared using ANOVA and Kruskal-Wallis test for continuous variables and Chi-square (X²) test for categorical variables. We used Cox regression analyses to evaluate survival, adjusted for age, gender, time on dialysis, diabetic status, Charlson comorbidity index (CI), type of vascular access, body mass index (BMI), dialysis adequacy (eKt/V), interdialytic fluid gain, intradialytic blood flow, hemoglobin, albumin, calcium and phosphorus. Results were presented as hazard ratios (HR) and 95% confidence intervals (95% CI) and a p-value below 0.05 was considered statistically significant. Results A total of 4,820 occurred during the period, 28% of which meeting the criteria for sudden death. Of all the sudden deaths, 34.1% were attributed to a cardiac event and 65.9% to unknown causes. The sudden death occurred more significantly in patients of male gender, longer time on dialysis, diabetic, higher BMI, higher fluid gain between HD treatments, higher blood flow during the treatment, use of central venous catheter as dialysis access and higher levels of hemoglobin, albumin and phosphorus. No differences between groups were found in age, CI and eKt/V. In the survival analysis, diabetics status, presence of a tunneled catheter and higher values of plasmatic phosphorus were independently associated with higher HR of sudden death (Table 1). Conclusion Sudden death is a common phenomenon in HD patients, being responsible for more than a quarter of all deaths. In our population, diabetes, the presence of a tunneled central venous catheter and higher phosphate levels were independently associated with a higher risk of SD. Our findings may provide preliminary evidence on some modifiable factors related to SD in HD patients and create the basis for the implementation of multidimensional interventions aiming at reducing the occurrence of sudden fatal events in this population.