Atrial fibrillation during hospitalization in an unselected cohort of hematopoietic stem cell transplant recipients. ARCA-TPH Registry

Abstract Background/Introduction Hematopoietic stem cell transplant (HSCT) has expanded in recent years to include older patients with more comorbidities, including cardiovascular risk factors. Atrial fibrillation (AF) has been described as a potential cardiovascular event during hospitalization in these patients. Purpose The aim of our study was to evaluate the incidence and risk factors of AF during hospitalization in an unselected cohort of hematopoietic stem cell transplant recipients at our center. Methods We conducted a single-center retrospective cohort study of consecutive HSCT recipients from 2018 to 2022. We reviewed the incidence of AF during hospitalization, as well as its management during admission and at discharge. Demographic variables, cardiovascular risk factors, comorbidities, transplant type, hematologic disease type, chemotherapy treatment, baseline echocardiogram, laboratory tests, and events during hospitalization and after one year were collected. Results A total of 394 patients were included, of whom 17 (4.3%) developed AF during hospitalization. The mean age was 58 ± 13 years, and 39.9% were female. AF was slightly more frequent in the autologous transplant group (4.6%) than in the allogeneic transplant group (3.9%) (p=0.45). Patients who developed atrial fibrillation had a mean age of 65 ± 7 years, a high burden of cardiovascular risk factors (29.4% smokers, 41.2% hypertension, 23.4% dyslipidemia, and 5.8% diabetes mellitus). Baseline echocardiogram showed mean LVEF of 64 ± 6.7%. Rate control was chosen in 47% of cases, while rhythm control was selected in another 47%. Electrical cardioversion was required in 11.8% of patients after failed pharmacologic rhythm control or hemodynamically unstable. Two patients died during hospitalization due to non-cardiovascular reasons. All patients were in sinus rhythm at discharge, and only two patients (11.8%) experienced recurrence post-discharge. The occurrence of atrial fibrillation was significantly associated with older age (58 ± 13 vs 65 ± 7; p=0.02) acute kidney injury during hospitalization (3.3 vs 10.7%; p=0.02), respiratory failure (3.5 vs 20%; p<0.01), and venous thrombosis (3.7 vs 17.6%; p=0.02). No significant association was found with pretransplant cardiovascular risk factors, other comorbidities or drug treatment. Conclusion(s) The prevalence of atrial fibrillation during hospitalization in HSCT recipients is not uncommon. It´s antiarrhythmic and antithrombotic management during hospitalization is heterogeneous. All patients were discharged in sinus rhythm, and recurrences were rare. AF was strongly associated with older age, acute kidney injury, respiratory failure, and venous thrombosis during hospitalization and classic cardiovascular risk factors didn´t seem to play a significant role. Therefore, special attention is required for patients who experience other complications during their hospital stay.