Relationship between mortality and speed of eGFR decline in the 3 months prior to dialysis initiation

Background: The timing for initiating dialysis in chronic kidney disease is often determined by the clinical symptoms and estimated glomerular filtration rate (eGFR). However, very few studies have examined how the speed of kidney function decline before initiating dialysis relates to mortality after dialysis initiation. Here, we report our examination of the relationship between the speed of eGFR decline in the 3 months prior to dialysis initiation and mortality. Methods: The study included 1292 new dialysis patients who were registered in the Aichi Cohort Study of Prognosis in Patients Newly Initiated into Dialysis. The subjects were placed in 4 groups based on the speed of eGFR decline in the 3 months before initiating dialysis (eGFR at 3 months before initiation—eGFR at initiation) <2: ≥2, <4: ≥4, <6: ≥6 mL/min/1.73 m². All-cause, cardiovascular, and infection-related mortality rates were compared using Kaplan–Meier curves. A multivariate analysis using the Cox proportional hazard model was used to extract the factors that contributed to all-cause mortality. Results: The group with faster eGFR decline exhibited significantly more heart failure symptoms when dialysis was initiated. Rapid eGFR decline correlated with prognosis (log-rank test: all-cause mortality p < 0.001, cardiovascular mortality p < 0.001). The speed of eGFR decline was related to elevated all-cause mortality rates [eGFR decline 10 mL/min/1.73 m², HR (95 % CI) = 1.53 (1.12–2.08)]. Conclusions: This study showed that patients with rapid eGFR decline in the 3 months before initiating dialysis more often presented with heart failure symptoms when dialysis was initiated and had poorer survival prognoses.