Abstract
<title>Abstract</title> <p> <bold>Introduction</bold> Atrial fibrillation (AF) is the most common acute cardiovascular complication following hematopoietic cell transplant (HCT). However, the incidence and risk factors for early-onset AF post-HCT remain poorly understood. <bold>Methods</bold> A retrospective cohort study was conducted to assess the onset and risk factors of AF within 90 days post-HCT in 5,965 adult transplant recipients. Patients underwent either allogeneic HCT (alloHCT, n = 2,742) or autologous HCT (autoHCT, n = 3,223) between January 1st, 2010 and December 31st, 2023. Cumulative incidence curves and Gray’s tests were used to assess AF cumulative incidence. Fine-Gary proportional sub-distributional hazard models were applied to estimate associations between factors and AF risk. <bold>Results</bold> Among patients without prior arrhythmia, cardiac disease, or valvular heart disease, AF occurred more frequently in alloHCT recipients than in autoHCT recipients (6.3% vs. 4.3%, Gray’s test <italic>P</italic> < 0.001). The median age was 54 years (range: 18–82) for alloHCT and 59 years (range: 18–78) for autoHCT. In alloHCT recipients, increased AF risk was associated with older age (≥ 50 vs. <50 years, adjusted hazard ratio (HR) = 2.85, <italic>P</italic> < 0.0001) and lower Karnofsky performance score (KPS, < 80 vs. ≥80, adjusted HR = 1.69, <italic>P</italic> = 0.03). In autoHCT recipients, increased AF risk was associated with older age (adjusted HR = 2.49, <italic>P</italic> = 0.006), lower KPS (adjusted HR = 2.41, <italic>P</italic> = 0.0001) and obesity (adjusted HR = 1.68, <italic>P</italic> = 0.015). <bold>Conclusion(s)</bold> This study indicates that AF cumulative incidence within 90 days post-HCT is higher in alloHCT than in autoHCT patients. Transplant recipients with older age, lower KPS, or obesity have an increased risk for early onset of AF post-HCT. </p>