Effect of estimated glomerular filtration rate (eGFR) on incidence of out-of-hospital cardiac arrests: A case-control study

Objectives: Serum creatinine levels in the post-resuscitative state have been associated with poor prognosis for out-of-hospital cardiac arrest (OHCA). Several studies have focused on kidney dysfunction in the general population, and the results suggested that serum creatinine level elevation or reduction of the estimated glomerular filtration rate (eGFR) are associated with increased risk of death and cardiovascular events. However, it is uncertain whether the serum creatinine levels or eGFR of OHCA patients are related to the incidence of OHCA. The aim of this study was to determine the association between eGFR and the incidence of OHCA.

Methods: This study was a case-control study performed using the Cardiac Arrest Pursuit Trial with Unique Registration and Epidemiologic Surveillance (CAPTURES) project dataset and the Korea National Health and Nutrition Examination Survey (KNHANES) dataset. Cases were defined as emergency medical service-treated adult OHCA patients with presumed cardiac etiology collected from the CAPTURES dataset. Four controls from the KNHANES dataset were matched to one case based on age, gender, and county. Multivariable conditional logistic regression analysis was conducted to evaluate the effect of eGFR on the incidence of OHCA.

Results: A total of 1211 matched case-control pairs were included in the study analysis. We classified eGFR into 6 categories (≥90, 60-89, 45-59, 30-44, 15-29, and <15 mL/min/1.73 m²) according to the chronic kidney disease stage. Subjects with an eGFR ≥90 mL/min/1.73 m² were used as the reference group. In both the unadjusted and adjusted models, lower eGFR was significantly associated with OHCA incidence. The odds ratio (OR) for OHCA incidence increased sharply as the eGFR declined; the adjusted OR (95% CI) for OHCA incidence was 4.09 (2.81-5.95) with an eGFR of 60-89 mL/min/1.73 m², 36.59 (22.24-60.21) with an eGFR of 45-59 mL/min/1.73 m², 55.26(29.66-102.94) with an eGFR of 30-44 mL/min/1.73 m², 89.65 (37.25-215.79) with an eGFR of 15-29 mL/min/1.73 m², and 241.87 (73.49-796.01) with an eGFR of less than 15 mL/min/1.73 m².

Conclusion: In this study, we observed an association between reduced eGFR and the risk of OHCA incidence in a large, community-based population. Future prospective studies are needed to better understand how reduced renal function is associated with OHCA occurrence as well as the impact of intensive risk management and intervention of renal function on OHCA incidence.