Prognostic Value of Left Atrial Diameter in Chronic Kidney Disease: The KNOW-CKD Study

INTRODUCTION: Left atrial enlargement (LAE), a hallmark of heart failure with preserved ejection fraction (HFpEF), is prevalent in chronic kidney disease (CKD), but its prognostic value for cardio-renal outcomes remains unclear. We aimed to investigate the association between left atrial (LA) diameter and adverse cardio-renal outcomes in patients with non-dialysis CKD stages 1-5. METHODS: We conducted a prospective cohort analysis of 2,145 participants from the KNOW-CKD study. Participants were categorised by baseline LA diameter: <40 mm, 40-45 mm and >45 mm (LAE). Primary outcomes included kidney failure requiring renal replacement therapy (KFRT), expanded major adverse cardiovascular events (eMACE), and all-cause mortality during a median 9.3-year follow-up. Cox proportional hazards models were used to assess associations after adjusting for demographics, kidney function, cardiovascular risk factors and medications. RESULTS: LAE was present in 11.5% of participants. Cumulative incidence of all outcomes increased significantly across LA diameter categories (log-rank P < 0.001 for all). After multivariable adjustment, LAE independently predicted KFRT (adjusted HR 1.60, 95% CI 1.23-2.08, P < 0.001) and eMACE (adjusted HR 1.80, 95% CI 1.10-2.96, P = 0.020), but not all-cause death (adjusted HR 1.25, 95% CI 0.83-1.87, P = 0.286). LA diameter correlated strongly with echocardiographic markers of diastolic dysfunction (E/e' ratio, r = 0.412, P < 0.001; LVMI, r = 0.296, P < 0.001) but not with left ventricular ejection fraction (r = -0.037, P = 0.096). CONCLUSION: In patients with non-dialysis CKD, LA diameter represents an accessible and independent prognostic marker for adverse kidney and cardiovascular outcomes. These findings support the integration of LA diameter assessment into routine cardiovascular risk stratification protocols for CKD patients.