Atrial fibrillation in allogeneic and autologous hematopoietic stem cell transplant recipients: incidence and clinical implications

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. 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-Gray proportional sub-distributional hazard models were applied to estimate associations between factors and AF risk. 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 P < 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 (sHR = 2.85, P < 0.0001) and lower Karnofsky performance score (KPS, < 80 vs. ≥80, adjusted sHR = 1.69, P = 0.03). In autoHCT recipients, increased AF risk was associated with older age (adjusted sHR = 2.49, P = 0.006), lower KPS (adjusted sHR = 2.41, P = 0.0001) and obesity (adjusted sHR = 1.68, P = 0.015). 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.