Patient characteristics and practice patterns among patients with endocarditis and dialysis-requiring acute kidney injury

Background Infective endocarditis (IE) may be complicated by acute kidney injury (AKI) and may in turn require dialysis. However, detailed data on patient characteristics and treatment trajectory before and during IE admission remain sparse. Identifying patients at high risk of dialysis-requiring AKI could provide important prognostic information and may elucidate areas for preventive strategies. Purpose This study aimed to describe patient characteristics and practice patterns of those who developed dialysis-requiring AKI during their IE-admission at a granular level. Methods Using data from the novel National Danish endocarditis studies (NIDUS) registry, we examined all patients admitted with IE in Denmark from 2016 to 2021. The study included all dialysis-naïve patients with first-time left-sided IE and categorized them into those with- and without dialysis-requiring AKI. We reported the pre-existing comorbidities, clinical presentation at admission, microbiological etiology, surgical treatment and complications during admission, and in-hospital mortality. Results We identified 2,738 patients with first-time IE; 203 (7%) had dialysis-requiring AKI (70% male, median age 70 years) and 2,535 (93%) did not undergo dialysis treatment (66% male, median age 75 years). Before admission, patients with AKI had a higher burden of comorbidities including known kidney disease (27% vs 11%), diabetes mellitus (31% vs 21%), and previous heart valve surgery (32% vs 27%). The most common bacterial etiology was Staphylococcus aureus (44%) for patient with dialysis while patients without dialysis were infected equally often by Streptococcus spp. (34%) and Staphylococcus aureus (30%). Dialysis patients had a larger median length of vegetation at diagnosis (median size 13 mm vs 10 mm) and more often suffered from sepsis during admission (36% vs 22%). More patients requiring dialysis underwent heart valve surgery (53% vs. 19%), with dialysis initiated after surgery in 92% of these cases. Dialysis patients had longer median length of hospital stay (50 days vs 35 days) and a markedly higher in-hospital mortality (38% vs 17%). Conclusion Patients admitted for IE who developed dialysis-requiring AKI is a high-risk group of patients and merits increased clinical awareness.