CATHETER ABLATION FOR SCREENING-DETECTED ATRIAL FIBRILLATION AND PRESERVED KIDNEY FUNCTION IN WORKING-AGE ADULTS: A NATIONWIDE COHORT STUDY WITH A TARGET TRIAL EMULATION FRAMEWORK

Atrial fibrillation (AF) is a common arrhythmia and is sometimes incidentally detected on screening electrocardiograms (ECGs). While AF and chronic kidney disease (CKD) are common co-existing conditions, the association of rhythm control therapies for screening-detected AF and subsequent kidney function remains unclear, particularly among working-age adults. Leveraging Japan’s unique setting where annual health screening is provided for all working-age citizens, we therefore aimed to emulate a target trial to assess the effect of catheter ablation for screening-detected AF on subsequent changes in estimated glomerular filtration rate (eGFR) in a general working-age population.

This retrospective cohort study used annual health screening and insurance claims records from the Japan Health Insurance Association from April 1, 2015, to March 31, 2023. The annual screening included routine ECG and eGFR measurement. We first identified individuals aged 35–59 who received health screening in the 2016–2018 health screening cycles and had no prior history of AF, cardiovascular comorbidities, or end-stage renal disease. Among these, participants with AF detected on the screening ECGs were included. To align treatment assignment and follow-up initiation, we implemented a time-sequential target trial emulation with propensity-score matching. On each date within one year after AF detection, individuals undergoing catheter ablation were matched 1:1 to those who had not yet received ablation by that date. Patients were followed until death, dialysis initiation, or deviation from the assigned treatment strategy. The primary outcome was the change in eGFR at subsequent annual health screenings, accounting for censoring bias using inverse probability of censoring weighting. The secondary outcome was the prevalence of sinus rhythm at subsequent screenings.

Among 9,227,066 health screening attendees, 10,610 had screening-detected AF; of these, 5,395 met eligibility criteria and 526 underwent catheter ablation within one year. After matching, 966 individuals (483 per group) were included in the analysis. The mean (standard deviation) age was 51.9 (5.8) years, 7.5% (72) were females, mean eGFR was 71.9 (13.3) mL/min/1.73m2, and 8.5% (82) had proteinuria. The 3-year follow-up rate was 80.6%. From baseline, the mean eGFR changes one year later was +3.8 mL/min/1.73m2 (95% confidence interval [CI], 2.9 to 4.7) in the ablation group versus -0.1 mL/min/1.73m2 (95%CI, -0.8 to 0.7) in the non-ablation group (difference, +3.9; 95%CI, 2.7 to 5.1, p<0.001). Two years later, the corresponding changes were +3.3 mL/min/1.73m2 (95%CI, 2.3 to 4.2) vs. -1.6 mL/min/1.73m2 (95%CI, -2.4 to -0.7) (difference, +4.8; 95%CI, 3.6 to 6.1, p<0.001), and three years later, +2.2 mL/min/1.73m2 (95%CI, 1.2 to 3.2) vs. -2.3 mL/min/1.73m2 (95%CI, -3.4 to -1.2) (difference, +4.5; 95%CI, 3.0 to 6.0, p<0.001). Three years later, sinus rhythm was confirmed in 97.4% of the ablation group and 40.5% of the non-ablation group.

In this emulated nationwide trial among Japanese working-age adults, catheter ablation for screening-detected AF was associated with preservation of kidney function, and a more favorable eGFR trajectory over three years compared to no intervention. This renal benefit coincide with a high rate of sinus rhythm maintenance, suggesting that rhythm control for incidentally detected AF may contribute to long-term kidney health.