The left atrioventricular coupling index (LACI) evaluates the coupling function between the left atrial (LA) and left ventricular (LV) chambers. However, little is known about LACI in chronic kidney disease (CKD) patients. This study aimed to assess the impact of concurrent CKD and type 2 diabetes mellitus (T2DM) on left atrioventricular coupling function compared to CKD patients without T2DM. A retrospective analysis included 173 CKD 4-5 stage patients who underwent echocardiographic examinations. The study comprised 75 CKD patients with T2DM (CKD + DM) and 98 CKD patients without T2DM (CKD-DM). During the follow-up, major adverse cardiac events (MACE) were tracked until June 30, 2024, or death, with a median duration of 21 (18, 27) months, 20.8% of patients experienced MACE, and 10.4% passed away. This study employed speckle tracking echocardiography to evaluate LA and LV strain, alongside the LACI, analyzing its role in predicting MACE. CKD + DM patients showed a notable rise in LACI compared to CKD-DM patients, hinting at a link between diabetes and impaired left atrioventricular coupling in CKD. Patients with lower LACI had superior clinical outcomes during follow-up (P <
0.001). Univariate and multivariate Cox regression analyses underscored LACI as an independent predictor for heightened MACE risk in CKD 4-5 stage patients. This study highlights a potential association between diabetes and impaired left atrioventricular coupling function in CKD 4-5 stage patients, with LACI independently linked to an increased risk of MACE.