Clinical factors for predicting cardiovascular risk, need for renal replacement therapy, and mortality in patients with non-dialysis-dependent stage 3-5 chronic kidney disease from the Salford Kidney Study.

Background: Established cardiovascular risk assessment tools lack chronic kidney disease-specific clinical factors and may underestimate cardiovascular risk in non-dialysis-dependent chronic kidney disease (CKD) patients.

Methods: A retrospective analysis of a cohort of patients with stage 3-5 non-dialysis-dependent chronic kidney disease in the Salford Kidney Study (UK, 2002-2016) was performed. Multivariable Cox regression models with backward selection and repeated measures joint models were used to evaluate clinical risk factors associated with cardiovascular events (individual and composite cardiovascular major adverse cardiovascular events), mortality (all-cause and cardiovascular-specific), and need for renal replacement therapy. Models were established using 70% of the cohort and validated on the remaining 30%. Hazard ratios ([95% CIs]) were reported.

Results: Among 2192 patients, mean follow-up was 5.6 years. Cardiovascular major adverse cardiovascular events occurred in 422 (19.3%) patients; predictors included prior history of diabetes (1.39 [1.13-1.71]; P = 0.002) and serum albumin reduction of 5 g/L (1.20 [1.05-1.36]; P = 0.006). All-cause mortality occurred in 740 (33.4%) patients, median time to death was 3.8 years; predictors included reduction of estimated glomerular filtration of 5 mL/min/1.73 m (1.05 [1.01-1.08]; P = 0.011) and increase of phosphate of 0.1 mmol/L (1.04 [1.01-1.08]; P = 0.021), whereas a 10 g/L hemoglobin increase was protective (0.90 [0.85-0.95]; P < 0.001). In 394 (18.0%) patients who received renal replacement therapy, median time to event was 2.3 years; predictors included halving of estimated glomerular filtration rate (3.40 [2.65-4.35]; P < 0.001) and antihypertensive use (1.23 [1.12-1.34]; P < 0.001). Increasing age, albumin reduction, and prior history of diabetes or cardiovascular disease were risk factors for all outcomes except renal replacement therapy.

Conclusions: Several chronic kidney disease-specific cardiovascular risk factors were associated with increased mortality and cardiovascular event risk in patients with non-dialysis-dependent chronic kidney disease.