Chronic kidney disease markers as independent risk factors for incident atrial fibrillation

Irregular heart rhythm or atrial fibrillation (AF) leads to serious complications, such as blood clotting and stroke, and, globally, new-onset or incident AF cases are on the rise. AF and chronic kidney disease (CKD) are closely linked, with CKD patients often experiencing AF, and vice versa, likely because both disorders share underlying pathophysiology (e.g. inflammatory/antioxidative pathway and enlargement of left atrium) and risk factors (e.g. age and diabetes). 

Despite the worldwide increase of both CKD and incident AF, no studies so far have shown a direct association between CKD and incident AF. 

In their systematic review and meta-analysis, Ha et al (2023) investigated if the two CKD markers – low estimated glomerular filtration rate (eGFR) and albuminuria – are associated with an increased risk of incident AF. Analysing 38 cohort studies and randomised clinical trials that had assessed AF incidence in adults as per baseline eGFR and/or albuminuria (total n=28,470,249), age- or multivariate-adjusted risk ratios were used to estimate the incident AF risk. 

The authors found that the participants were at a greater risk of incident AF if they had any CKD markers: eGFR of <60 vs ≥60 mL/min/1.73 m² and normal-to-mild vs moderate-to-severe albuminuria increased incident AF risk by 43%–64%. This remained true when previously known AF risk factors were adjusted for, indicating an independent association between baseline kidney function and incident AF risk.

In the subgroup analyses, the authors reported an increase in the adjusted incident AF risk proportional to the baseline CKD severity: progressively lower eGFR or progressively higher albuminuria led to a proportionate increase in incident AF risk. 

This study does not include direct patient-level data, and the AF detection methods may vary amongst published studies; the interaction of eGFR and albuminuria with each other is also unclear from these data. 

However, the authors show a clear association between CKD markers and increased incident AF risk. They conclude that CKD should not only be considered an independent risk factor for incident AF, but that AF clinical trials should include participants with CKD so that we can create better screening and early interventions for AF, especially as several effective CKD treatments have recently been launched. 

The shared burden of CKD and AF worsens patient outcomes. This study provides a step in the right direction towards lightening this load. 

Reference

Ha JT, Freedman SB, Kelly DM et al (2023) Kidney function, albuminuria and risk of incident atrial fibrillation: A systematic review and meta-analysis. Am J Kidney Dis 28 Sept [Epub ahead of print]