Long-term trajectory of estimated glomerular filtration rate in ambulatory patients with type 2 diabetes and heart failure: clinical insights and prognostic implications.

Background: Although previous studies have evaluated renal function decline in patients with heart failure (HF), there is limited evidence on long-term renal trajectories, especially in patients with concomitant HF and type 2 diabetes (T2D). This study aims to provide a detailed analysis of renal function decline over an extended follow-up period in a well-characterized cohort of patients with HF and T2D.

Methods: This is a post hoc subanalysis of a prospective registry involving ambulatory patients with HF and T2D referred to a specialized HF clinic. The estimated glomerular filtration rate (eGFR) was assessed at baseline and during scheduled follow-up visits every three months using the Chronic Kidney Disease Epidemiology Collaboration formula. Loess curves were plotted for predefined subgroups, and multivariable longitudinal Cox regression analyses were performed to evaluate the associations between eGFR trajectories and all-cause mortality.

Results: A total of 1,114 patients with HF and T2D were included, with a mean age of 69.3 ± 10.3 years, and 68.2% were men. In total, 10,830 scheduled creatinine measurements were analysed, with a mean of 15.8 ± 9.4 measurements per patient. A significant progressive decline in the eGFR was observed, with an average annual rate of - 2.05 (95% CI - 2.11 to - 1.95, p < 0.001) ml/min/1.73 m. Subgroup analysis indicated that older age, nonischaemic HF aetiology, HFpEF or HFmrEF, poor glycaemic control, and higher baseline eGFRs were associated with a more pronounced decline in renal function. Furthermore, a decrease in the eGFR was independently associated with an increased risk of all-cause mortality.

Conclusions: This study offers novel insights into long-term renal function trajectories in patients with HF and T2D and identifies key clinical factors associated with accelerated renal decline. Future research is warranted to validate these results in larger, more diverse cohorts and to explore potential therapeutic interventions.