Oral anticoagulation to prevent thrombosis recurrence in polycythemia vera and essential thrombocythemia

Abstract

It is unclear whether anticoagulation guidelines intended for the general population are applicable to patients with polycythemia vera (PV) and essential thrombocythemia (ET). In the present study, the risk of thrombotic recurrence was analyzed in 150 patients with PV and ET treated with vitamin K antagonists (VKA) because of an arterial or venous thrombosis. After an observation period of 963 patient-years, the incidence of re-thrombosis was 4.5 and 12 per 100 patient-years under VKA therapy and after stopping it, respectively (P < 0.0005). After a multivariate adjustment for other prognostic factors, VKA treatment was associated with a 2.8-fold reduction in the risk of thrombotic recurrence. Notably, VKA therapy offset the increased risk of re-thrombosis associated with a prior history of remote thrombosis. Both the protective effect of VKA therapy and the predisposing factors for recurrence were independent of the anatomical site involved in the index thrombosis. Treatment periods with VKA did not result in a higher incidence of major bleeding as compared with those without VKA. These findings support the use of long-term anticoagulation for the secondary prevention of thrombosis in patients with PV and ET, particularly in those with history of remote thrombosis.

High risk of recurrent venous thromboembolism in BCR-ABL-negative myeloproliferative neoplasms after termination of anticoagulation

“…In our study, the incidence for a VTE recurrence was 6.0% patient/year and thus was comparable to VTE recurrence rates reported in the literature with 2.7-12% patient-year ( 10,15,17 ). Remarkably, the VTE recurrence rate in MPN is up to 3-times higher compared with non-MPN patients, where recurrence rates of VTE are reported in the range of 0.5-3.5% patient-year ( 14,31 ).…”

Splanchnic vein thromboses associated with myeloproliferative neoplasms: An international, retrospective study on 518 cases

“…Though there is a general agreement in maintaining long‐term anticoagulation, valuing the underlying hematological disorder as a permanent risk factor, recurrent thromboses ‐ either SVT or not ‐ are reported in a non‐trivial proportion of MPN‐SVT, ranging from 16%‐17% to 27% . While in the general population VKA are effective after venous thromboembolism at usual sites, their efficacy and safety are overall less favorable in MPN patients, with higher rates of recurrences and major bleeding, particularly when dealing with thromboses at unusual sites, as SVT or CVT . In a large (n = 181), contemporary cohort of MPN‐SVT, rate of major bleeding was reported to be 2.1 (95% CI 1.3‐3.5) per 100 patient‐years, which is higher than expected for non‐splanchnic deep venous thromboses in the general population treated with VKA (0.9 [95% CI 0.4 to 3.0] per 100 patient‐years) …”

How to Treat Essential Thrombocythemia and Polycythemia Vera

“…Both the protective effect of VKA therapy and the predisposing factors for recurrence were independent of the anatomical site involved in the first thrombotic event leading to anticoagulant treatment. Treatment periods with VKA did not result in a higher incidence of major bleeding as compared with those without VKA 21 .…”