Kidney function and the risk of sudden cardiac death in the general population

Background Chronic kidney disease increases sudden cardiac death (SCD) risk, but the association between kidney function and SCD in a general population is largely unknown. Therefore, we investigated the association between kidney function and SCD in a general middle-aged and elderly population. Methods We included individuals aged ≥45 years from a prospective population-based cohort study. The association between kidney function assessments [estimated glomerular filtration rate based on serum creatinine (eGFRcreat), cystatin C (eGFRcys) or both (eGFRcreat-cys)] and SCD was investigated using Cox proportional-hazards and joint models. Absolute 10-year risks were computed using competing risk analyses. Mediation analyses were performed using a four-way decomposition method. Results We included 9687 participants (median follow-up 8.9 years; mean age 65.3 years; 56.7% women; 243 SCD cases). Lower eGFRcys and eGFRcreat-cys were associated with increased SCD risk [hazard ratio (HR) 1.23, 95% confidence interval (CI) 1.12–1.34 and HR 1.17, 95% CI 1.06–1.29, per 10 mL/min/1.73 m2 eGFR decrease]. A significant trend (P = 0.001) across eGFRcys categories was found, with an HR of 2.11 (95% CI 1.19–3.74) for eGFRcys 90 mL/min/1.73 m2. Comparing eGFRcys of 90 to 60 mL/min/1.73 m2, absolute 10-year risk increased from 1.0% to 2.5%. Identified subgroups at increased risk included older participants and participants with atrial fibrillation. The associations were not mediated by coronary heart disease, hypertension or diabetes. Conclusions Reduced kidney function is associated with increased SCD risk in the general population, especially with eGFRcys. eGFRcys could be added to prediction models and screening programmes for SCD prevention.