Combined Effects of Intradialytic Hypotension, Interdialytic Weight Gain Ratio, NLR, and SII on Cardiocerebrovascular Outcomes in Maintenance Hemodialysis

Cardiocerebrovascular complications remain a major source of morbidity and mortality among patients receiving maintenance hemodialysis. Hemodynamic instability during dialysis, fluid accumulation between treatments, and chronic systemic inflammation may contribute through distinct but potentially overlapping pathways. This study evaluated the individual and combined associations of intradialytic hypotension, interdialytic weight gain ratio, neutrophil-to-lymphocyte ratio, and systemic immune-inflammation index with incident cardiocerebrovascular events. This single-center retrospective cohort study included 110 adults receiving maintenance hemodialysis. Baseline clinical, dialysis-related, and laboratory variables were assessed from January through March 2025, and incident cardiocerebrovascular events were ascertained from April through December 2025. Frequent intradialytic hypotension was defined according to the binary classification recorded in the dialysis database. NLR and SII were recalculated from baseline blood-cell counts. Associations with the composite outcome were evaluated using Firth penalized logistic regression. Separate NLR- and SII-based combined models included intradialytic hypotension, interdialytic weight gain ratio, age, and pre-existing coronary heart disease. Internal validation was performed using 1,000 bootstrap resamples. During follow-up, 22 patients experienced an incident cardiocerebrovascular event, corresponding to a cumulative event proportion of 20.0%. Acute heart failure accounted for 16 events, while three acute coronary events and three ischemic cerebrovascular events were recorded. Frequent intradialytic hypotension was present in 83.6% of the cohort. In exposure-specific adjusted models, frequent intradialytic hypotension was associated with an odds ratio of 0.60 (95% confidence interval, 0.19–1.95), interdialytic weight gain ratio with an odds ratio of 1.03 per 1% increase (0.81–1.31), ln-transformed NLR with an odds ratio of 0.85 (0.36–2.00), and ln-transformed SII with an odds ratio of 0.99 (0.47–2.10). None of these associations was statistically significant. The apparent areas under the receiver operating characteristic curve were 0.655 for the NLR-based model and 0.658 for the SII-based model, decreasing to 0.548 and 0.549 after optimism correction. In this cohort, binary intradialytic hypotension, interdialytic weight gain ratio, NLR, and SII were not independently associated with short-term cardiocerebrovascular outcomes. Their combined use provided limited discrimination after internal validation. Repeated session-level assessment of blood pressure instability, fluid exposure, and inflammatory status may be required to characterize their cumulative cardiovascular effects more accurately.