Acute kidney injury is linked to higher mortality in elderly hospitalized patients with non-valvular atrial fibrillation.

Renal insufficiency is associated with medical complications in patients with non-valvular atrial fibrillation (NVAF). However, data for elderly patients are scarce. Thus, the main objectives of the present study were to analyze the characteristics of elderly patients with NVAF and acute or chronic renal disease, describe their management in real-life conditions, and detect factors associated with complications. The NONAVASC registry includes patients > 75 years with NVAF, hospitalized by any cause in 64 Spanish Internal Medicine departments. Patients were categorized into acute kidney injury (AKI), chronic kidney disease (CKD) or preserved renal function (PRF). All variables associated with in-hospital mortality with P < 0.10 in univariate analysis were included to develop a multivariate logistic-regression model. The study included 804 patients (53.9% women), 352 (43.8%) of whom met diagnostic criteria for CKD. AKI was detected in 119 (14.8%) patients. AKI was associated with greater length of stay, higher mortality and an increased rate of patient transfer to nursing homes. After logistic-regression analysis, we found an association between mortality and AKI (OR 2.4, 95% CI 1.03-5.53; P = 0.045). The increase in creatinine values (OR 1.8, 95% CI 1.19-2.73; P = 0.005) and the decrease in albumin values (OR 2.0, 95% CI 1.05-3.73; P = 0.033) were also linked to mortality. Our study shows the relationship between AKI and creatinine value increase and a higher mortality in elderly patients with NVAF. In light of our findings, the detection of renal function impairment in these patients should alert physicians and consider them as high-risk patients.