Impact of renal-replacement therapy strategies on outcomes for patients with chronic kidney disease: a secondary analysis of the STARRT-AKI trial

Purpose To assess whether pre-existing chronic kidney disease (CKD) modified the relationship between the strategy for renal-replacement theraphy (RRT) initiation and clinical outcomes in the STARRT-AKI trial. Methods This was a secondary analysis of a multi-national randomized trial. We included patients who had documented pre-existing estimated glomerular filtration rate (eGFR) data prior to hospitalization, and we defined CKD as an eGFR ≤ 59 mL/min/1.73 m 2 . The primary outcome was all-cause mortality at 90 days. Secondary outcomes included RRT dependence and RRT-free days at 90 days. We used logistic and linear regression and interaction testing to explore the effect of RRT initiation strategy on outcomes by CKD status. Results We studied 1121 patients who had pre-hospital measures of kidney function. Of these, 432 patients (38.5%) had CKD. The median (IQR) baseline serum creatinine was 130 (114–160) and 76 (64–90) µmol/L for those with and without CKD, respectively. Patients with CKD were older and more likely to have cardiovascular comorbidities and diabetes mellitus. Patients with CKD had higher 90-day mortality (47% vs. 40%, p