Impact of worsening renal function detected at emergency department arrival on acute heart failure short-term outcomes

Background and importance Deterioration of renal function with respect to baseline during an acute heart failure (AHF) episode is frequent, but impact on outcomes is still a matter of debate. Objective To investigate the association of creatinine deterioration detected at emergency department (ED) arrival and short-term outcomes in patients with AHF. Design Secondary analysis of a large multipurpose registry. Settings and participants Patients with AHF were diagnosed in 10 Spanish ED for whom a previous baseline creatinine was available. Exposure Difference between creatinine at ED arrival and at baseline was calculated (∂-creatinine). Outcome measures and analysis Primary outcome was 30-day all-cause death, and secondary outcomes were inhospital all-cause death, prolonged hospitalization (>7 days) and 7-day postdischarge adverse events. Associations between ∂-creatinine and outcomes were explored using logistic regression by restricted cubic spline (RCS) curves and expressed as odds ratio (OR) with 95% confidence interval (CI), taking ∂-creatinine = 0 mg/dl as reference. Curves were adjusted by age, sex, comorbidities, patient baseline status, chronic treatments, and vitals and laboratory results at ED arrival. Interactions for the primary outcome also were investigated. Main results We analyzed 3036 patients (median age = 82 years; IQR = 75–87; women = 55%), with ∂-creatinine ranged from −0.3 to 3 mg/dl. The 30-day mortality was 11.6%. Increments of ∂-creatinine were associated with progressive increase in risk of 30-day death, although adjustment attenuated this association: ∂-creatinine of 0.3/1/2/3 mg/dl were, respectively, associated with adjusted OR of 1.41 (1.02–1.95), 1.69 (1.02–2.80), 1.46 (0.56–3.80) and 1.27 (0.27–5.83). Distinctively significant higher risk was found for patients over 80 years old, female, nondiabetic, functionally disabled and on digoxin therapy. With respect to secondary outcomes, inhospital mortality was 8.1%, prolonged hospitalization was 33.6% and 7-day postdischarge adverse event was 9.7%. Inhospital death steadily increased with increments in ∂-creatinine [from 1.50 (1.04–2.17) with ∂-creatinine = 0.3 to 3.78 (0.78–18.3) with ∂-creatinine = 3], as well as prolonged hospitalization did [from 1.41 (1.11–1.77) to 2.24 (1.51–3.33), respectively]. Postdischarge adverse events were not associated with ∂-creatinine. Conclusion WRF detected at ED arrival has prognostic value in AHF, being associated with increased risk of death and prolonged hospitalization. These associations showed different patterns of risk but, remarkably, risk started with increments as low as 0.3 mg/dl.