Patient characteristics and prognostic importance of dialysis in IE - a nationwide study

• Dialysis patients were younger but had more comorbidities and advanced disease. • Factors linked to dialysis included surgery, CKD, diabetes, liver disease, and infection with Staphylococcus aureus and Enterococcus spp. • Dialysis marked a high-risk group with in-hospital mortality near 40%, corresponding to an almost two fold increased adjusted hazard compared with patients with no dialysis. • Among patients surviving the initial admission, initiation of dialysis was also linked to a higher risk of mortality during the early post-discharge period; however, this elevated risk diminished after three months. Acute kidney injury (AKI) requiring dialysis is a serious complication of infective endocarditis (IE), yet detailed data on risk factors and outcomes are limited. Using the nationwide NIDUS registry, we identified all dialysis-naive patients hospitalized with first-time left-sided IE in Denmark from 2016–2021. Patients were grouped by whether they developed dialysis-requiring AKI. Factors associated with dialysis were assessed with multivariable logistic regression. In-hospital and post-discharge mortality were evaluated using Kaplan–Meier methods and multivariable Cox models. Among 2,738 patients with left-sided IE, 203 (7%) received dialysis for AKI (70% male; median age 70 years) and 2,535 (93%) did not (66% male; median age 75 years). Those requiring dialysis had greater comorbidity, and more frequently underwent valvular surgery (57.0% vs 19.8%, p < 0.01), with two-thirds initiating dialysis postoperatively. Independent factors associated with initiation of dialysis included chronic kidney disease, diabetes, liver disease, sepsis, valvular surgery, and infection with Staphylococcus aureus or Enterococcus species. In-hospital mortality was substantially higher among patients requiring dialysis (37.9 vs 16.5%; HR 1.86, 95% CI 1.39-2.50). In-hospital mortality was higher with dialysis (37.9% vs 16.5%; HR 1.86, 95% CI 1.39-2.50). Among survivors, associated mortality was higher within 3 months (12.0% vs 9.0%; HR 2.35, 95% CI 1.30-4.27) but similar from 3 to 12 months (6.3% vs 11.3%; HR 0.89, 95% CI: 0.41-1.93). Patients initiating dialysis during IE had an increased burden of traditional risk factors for AKI – with valve surgery representing the strongest associated risk factor for initiating dialysis. Patients initiating dialysis during IE had a markedly higher in-hospital mortality. Among survivors, higher associated mortality was confined to the early post-discharge period and diminished after 3 months.