Prevalence, outcomes and costs of patients with renal dysfunction in the emergency department of a specialized cardiology hospital

ABSTRACT

INTRODUCTION: Chronic kidney disease and acute kidney injury (AKI) are important complications of heart diseases. In developing countries, epidemiological and cost information on the interaction of these conditions are scarce. OBJECTIVES: To determine the prevalence, costs and outcomes of patients admitted for acute coronary syndrome (ACS) with renal dysfunction and AKI. METHODS: The study was based on a prospective database analysis of patients admitted for ACS to a Brazilian public hospital specialized in cardiology between 7/16/2018 and 12/31/2019. Renal dysfunction was defined as an estimated glomerular filtration rate (eGFR) <60ml/min/1.73m² at hospital admission. Community-acquired and hospital-acquired AKI were defined as a fall and an increase of ≥0.3mg/dl in serum creatinine from baseline, respectively. RESULTS: 1295 of the 1620 patients had a confirmed diagnosis of ACS (median age 64.2 [56.5-70.6] years, 65.4% male, 82.7% had hypertension, 45.5% diabetes and 22.6% renal dysfunction). The imaging diagnosis of ACS was coronary angiography in 84.3% and the treatment was performed by angioplasty, only clinically and by myocardial revascularization in 47.3%, 40.0% and 12.7%, respectively. Hospital- and community-acquired AKI occurred in 43.9% and 2.3% of patients, respectively. Compared with patients admitted with eGFR ≥60ml/min/1.73m², those with eGFR <60 were older (70.6 vs. 62.5 years, p<0.001), had a higher prevalence of hypertension (92.1% vs. 80.0%, p<0.001) and diabetes mellitus (60.6% vs.54.5%, p=0.010), had a higher incidence of AKI (65.0% vs. 51.4%, p <0.001) and higher median amount reimbursed for hospitalization (1,344 [366-2,103] vs. 1,334 [290-2,018] dollars, p=0.034), median length of stay (5 [3-10] vs. 4 [2-7] days, p<0.001), death within 30 days (4.1% vs. 1.4%, p=0.004) and death within 12 months (9.2% vs. 2.9%, p<0.001). Patients with AKI, compared to those without this condition, were older (65.6 vs.63.3 years, p=0.008), had lower eGFR on admission (78.1 ml/min/1.73m² vs.86.1 ml/min/1.73m², p<0.001) and greater median amount reimbursed for hospitalization (1,334 [301-1,865] vs. 1,724 [973-2,549] dollars, p<0.001), median length of stay (6 [4-13] vs. 3 [2-5] days, p <0.001) and death within 12 months (4.8% vs. 2.3%, p=0.032). CONCLUSIONS: In patients with ACS at a cardiology referral hospital, renal dysfunction on admission and AKI during hospitalization were frequent and associated with worse clinical and economic outcomes.