Characterization of baseline clinical factors associated with incident worsening kidney function in patients with non-valvular atrial fibrillation: the Hokuriku-Plus AF Registry.

Evidence suggests that atrial fibrillation (AF) could increase the risk of worsening kidney function (WKF) which is linked to an increased risk of stroke, bleeding, and death in AF patients. However, limited data exist regarding the factors that could lead to WKF in these patients. Therefore, we sought to identify the potential factors associated with the development of WKF in patients with non-valvular AF (NVAF). We analyzed prospectively recruited 1122 NVAF patients [men 71.9%, median age 73.0 years (interquartile range: 66.0-79.0)] with a baseline estimated glomerular filtration rate (eGFR) ≥ 15 mL/min/1.73 m from the Hokuriku-Plus AF Registry. The primary outcome was incident WKF, defined as the %eGFR change from the baseline ≥ 30% during the follow-up period. We evaluated the association between baseline variables and incident WKF using univariate and multivariate Cox proportional hazard models. We also evaluated the non-linear association between the identified factors and incident WKF. During a median follow-up period of 3.0 years (interquartile range: 2.7-3.3), incident WKF was observed in 108 patients (32.6 per 1000 person-years). Compared to the patients without incident WKF, the patients with incident WKF were older and had a higher prevalence of heart failure (HF), diabetes mellitus (DM), and vascular disease at baseline. Those who experienced incident WKF also had higher diastolic blood pressure, lower hemoglobin, lower eGFR, higher B-type natriuretic peptide (BNP) and used warfarin more frequently. Upon multivariate analysis, age ≥ 75 years, HF, DM, and anemia were independently associated with incident WKF. Additionally, age and hemoglobin were linearly associated with the risk of incident WKF, whereas a J- or U-shaped association was observed for HbA1c and BNP. Age ≥ 75 years, HF, DM, and anemia were associated with the development of WKF in Japanese patients with NVAF. In patients with these risk factors, a careful monitoring of the kidney function and appropriate interventions may be important when possible.