The following is the summary of “Association of Intra-individual Differences in Estimated GFR by Creatinine Versus Cystatin C With Incident Heart Failure”published in the December 2022 issue of Kidney diseases by Chen, et al.

Increased risk of heart failure (HF) is seen in those with reduced eGFR. Nonetheless, there may be significant individual variation in estimated glomerular filtration rate (eGFR) calculated from cystatin C (eGFRcys) and creatinine (eGFRcr). The effects of these variations on the risk of HF in patients with chronic kidney disease (CKD) are not well understood from a clinical standpoint. Design of Study Future-looking cohort study. In the Chronic Renal Insufficiency Cohort (CRIC) Study, 4,512 persons with CKD and no evidence of widespread HF were followed over time. Variation in Predicted GFR Due to Exposure (eGFRdiff; ie, eGFRcys  minus eGFRcr). Hospitalization due to HF incident outcome.

Methodology Baseline, time-updated, and slope of eGFRdiff  were analyzed for their correlations with incident HF using Fine-Gray proportional sub hazards regression. One third of the 4,512 people studied exhibited a disparity between their eGFRcys and eGFRcr of more than 15 mL/min/1.73 m2. A greater probability of incident HF hospitalization was observed for every 15 mL/min/1.73 m2 lower baseline eGFRdiff  (hazard ratio [HR], 1.20 [95% CI, 1.07-1.34]). Those with an estimated glomerular filtration rate difference (eGFRdiff) of less than 15 mL/min/1.73 m2  had a higher risk of incident HF hospitalization (HR, 1.99 [95% CI, 1.39-2.86]) compared with participants with similar eGFRcys and eGFRcr, and those with an eGFRdiff  of 15 mL/min/1.73 m2 had a lower.

There was an increased risk of incident HF among participants whose eGFRcys fell more rapidly than their eGFRcr (HR, 1.49 [95% CI, 1.19-1.85]) compared to those whose eGFRcys  and eGFcr declined at similar rates. Baseline eGFRcr levels were limited, but eGFRcys were not for entry into the CRIC Study. When comparing individuals with CKD and a high disparity between their eGFRcys and eGFRcr, eGFRcys is more strongly related with the risk for incident HF. The risk of incident HF is independently linked with the degree to which eGFRcys and eGFRcr have diverging slopes over time.