Trends in the thrombotic complications of myeloproliferative neoplasms: A nationwide analysis.

6581 Background: Thrombotic complications are a well known cause of morbidity and mortality in Philadelphia-negative Myeloproliferative Neoplasms[Polycythemia Vera, Essential thrombocythemia, Primary Myelofibrosis]. Current study evaluated thrombotic events incidence and outcome trends in Myeloproliferative Neoplasms[MPN] from 2012 to 2020. Methods: This is a longitudinal study of thrombotic events in MPN using the Nationwide Inpatient Sample. All patients with a diagnosis of MPN admitted with any thrombotic event including arterial or venous thrombosis were included in the study. Arterial thrombotic events included Myocardial infarction[MI], Ischemic stroke[IS], Transient Ischemic Attack[TIA] while venous thrombotic events included Deep Vein Thrombosis[DVT], Pulmonary Embolism[PE], Budd-Chiari Syndrome[BCS], Portal Vein Thrombosis[PVT]. Thrombosis related inpatient mortality rate, incidence, length of hospital stay, and total hospital charges were calculated. Results: Mortality rate from any thrombotic event overall[arterial plus venous] increased from 2.3% to 2.6% from 2012 to 2020. There was an increase in mortality rates from 2.8% to 3.8% among arterial thrombosis while there was a decrease in venous thrombosis related mortality from 1.7 to 0.4%. Specifically MI and IS related mortality increased from 3.7% to 4.3% and 3% to 4% respectively over the same period. The incidence of any thrombotic event declined from 2 to 1.3 cases/100,000 persons from 2012 to 2020. A similar decline in incidence of arterial, venous events, MI, IS were observed. The mean length of stay decreased from 5.8 days in 2012 to 5.2 days in 2020 among MPN patients with venous thrombosis which was statistically significant. Similar decline was noted in MI patients as well. Though the mean length of stay increased from 7.9 to 9.5 days among MPN patients with IS, this increase was not statistically significant. The mean hospitalization charges for thrombotic events increased from $53,421 in 2012 to $101,598 in 2020 after adjusting for inflation. Similar trends were noted in all types of thrombotic admissions which were all statistically significant. Upon age based stratification of MPN, mortality for those less than 60 years reduced from 2% to 0.3%, while it increased from 4.1 to 5.6% in those more than 60 years from 2012 to 2020. Conclusions: Inpatient mortality from thrombotic events in MPN has shown an increasing trend from 2012 to 2020 though there was a decline in overall incidence of thrombosis during the same period. Despite the decreasing trend in length of stay, the total economic burden of thrombotic complications in MPN is increasing in the US. Specifically the effects were more pronounced in those greater than 60 years. This points to the need for revisiting guidelines regarding thromboprophylaxis in MPN.