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.