Abstract 350: Impact of Acute Kidney Injury on Outcomes of Patients Admitted with Unstable Angina in United States, Years 2005-2011

Abstract

Background: Acute kidney injury (AKI) in the setting of myocardial infarction is associated with poor outcomes. However, its impact on outcomes of unstable angina is unknown. We sought to determine the prevalence and effect of AKI on in-hospital outcomes of patients admitted with unstable angina (UA) in the United States. Methods: We obtained and analyzed data from Nationwide Inpatient Sample (NIS 2002- 2011). Study population included all adults (>18 years old) with the primary discharge diagnosis of UA and the secondary diagnosis of AKI. The associations of AKI with in-hospital complications, procedures, discharge outcomes and mortality, were analyzed after adjusting for potential confounders using logistic regression analyses. Results: During the study period, 541,948 patients were admitted with UA; of which, 18,882 (3.5%) had AKI and 64 (0.3%) required dialysis during the same hospitalization. Patients with AKI had significantly higher rates of in-hospital complications such as infections, venous thromboembolism, myocardial infarction, stroke and gastrointestinal bleeding but fewer (n= 565, 3%) of these patients received percutaneous transluminal angioplasty. After adjusting for all confounding factors, UA patients in the AKI group had higher odds of in-hospital death (odds ratio, 2.5; 95% confidence interval, 1.6-3.9; P<0.0001). On trend analysis, rates of AKI had declined from 17% in the year 2002 to 6% in the year 2011 (p<0.0001). In the year 2011, mean length of stay had reduced by an average of 1 day in comparison with the year 2005 (p<0.0001). Mortality in the AKI group did not change significantly over the 10 years study period. Conclusions: In patients with UA, AKI is associated with significantly higher rates of in-hospital complications and mortality.