Impact of Atrial Fibrillation on Thrombotic Complications in Myeloproliferative Neoplasms Real-World Analysis

Background Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) are clonal hematopoietic disorders characterized by an increased risk of thrombotic complications due to a persistent pro-thrombotic and inflammatory state. Atrial fibrillation (AF) is a common cardiac arrhythmia and an established risk factor for thromboembolism; however, its impact on thrombotic complications in patients with MPN remains incompletely characterized. Material and Methods This multicenter, real-world retrospective study analyzed 2,683 MPN patients diagnosed between 1976 and 2024 to investigate the impact of AF on thrombotic events, bleeding risk, and survival outcomes. Results Patients with MPN and AF (MPN-AF) had a higher rate of thrombotic events, with arterial thrombosis predominating (67% vs. 43%, p < 0.0001). Despite this arterial phenotype, 36.7% of MPN-AF patients did not receive antiplatelet therapy. Thrombosis rates remained high in AF patients despite cytoreductive therapy. Kaplan–Meier analysis revealed that AF was linked to significantly shorter overall survival (181 months vs. 265 months, HR: 1.86, 95% CI: 1.53–2.26, p < 0.0001), particularly in essential thrombocythemia and MF subtypes. Conclusion Our findings highlight that the thrombotic profile of MPN patients with AF differs from that observed in the general AF population, with a clear predominance of arterial events. Conventional AF management focused on anticoagulation may incompletely address the predominantly arterial thrombotic phenotype observed in MPN. The treatment patterns observed in our cohort–with frequent reliance on anticoagulation alone and limited use of antiplatelet therapy–suggest a need for more disease-adapted antithrombotic considerations in this subgroup. Prospective studies are needed to clarify the contribution of inflammatory and vascular mechanisms to thrombotic risk in MPN-AF.