LAUSR

Abstract Aims Haematopoietic stem cell transplantation (HSCT) is a potentially curative therapy for several malignant and non-malignant haematologic conditions. Patients undergoing HSCT are at an increased risk of developing atrial fibrillation (AF). We hypothesized that a diagnosis of AF would be associated with poor outcomes in patients undergoing HSCT. Methods and results The National Inpatient Sample (2016–19) was queried with ICD-10 codes to identify patients aged >50 years undergoing HSCT. Clinical outcomes were compared between patients with and without AF. A multivariable regression model adjusting for demographics and comorbidities was used to calculate the adjusted odds ratio (aOR) and regression coefficients with corresponding 95% confidence intervals and P-values. A total of 50 570 weighted hospitalizations for HSCT were identified, out of which 5820 (11.5%) had AF. Atrial fibrillation was found to be independently associated with higher inpatient mortality (aOR 2.75; 1.9–3.98; P < 0.001), cardiac arrest (aOR 2.86; 1.55–5.26; P = 0.001), acute kidney injury (aOR 1.89; 1.6–2.23; P < 0.001), acute heart failure exacerbation (aOR 5.01; 3.54–7.1; P < 0.001), cardiogenic shock (aOR 7.73; 3.17–18.8; P < 0.001), and acute respiratory failure (aOR 3.24; 2.56–4.1; P < 0.001) as well as higher mean length of stay (LOS) (+2.67; 1.79–3.55; P < 0.001) and cost of care (+67 529; 36 630–98 427; P < 0.001). Conclusion Among patients undergoing HSCT, AF was independently associated with poor in-hospital outcomes, higher LOS, and cost of care.