Incidence of thrombosis and bleeding in patients with JAK2- positive myeloproliferative neoplasms receiving low-dose aspirin: a systematic review and meta-analysis.

Background

Patients with JAK2V617F-positive myeloproliferative neoplasms (MPNs) are at increased thrombotic risk and commonly receive low-dose aspirin, yet its net clinical benefit is uncertain.

Objectives

We estimated the incidence of thrombotic and bleeding events in patients with JAK2-positive MPNs treated with low-dose aspirin.

Methods

A systematic review was performed for studies evaluating thrombotic and hemorrhagic events in patients with JAK2V617F-positive MPNs while taking low-dose aspirin. Study-level incidence rates (IR) per 100 person-years (PY) and incidence rate ratios (IRR) comparing aspirin use versus no aspirin were calculated and pooled using random-effects meta-analysis. The certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.

Results

We included 3 randomized clinical trials and 7 observational studies (n=1,760 with aspirin, n=367 without aspirin). The pooled IR of thrombotic events in JAK2V617F-positive MPN patients receiving low-dose aspirin prophylaxis was 2.72 per 100 PY (95% confidence interval (CI) 1.59 - 4.65; I2=93%) with pooled IRR receiving aspirin versus no aspirin of 0.59 (95% CI 0.40 - 0.86, I2=16%). The pooled IR of major and non-major bleeding on low-dose aspirin prophylaxis was 1.97 (95% CI 1.06 - 3.65; I2=90%) per 100 PY with pooled IRR of 2.43 (95% CI 1.15 - 5.11; I2=43%). The GRADE level of confidence for the investigated risks was low.

Conclusions

Aspirin was associated with a 40% reduction in thrombosis but a 2.5-fold increase in bleeding risk with low certainty of evidence. More studies are needed to gain high-quality evidence the better define the role of aspirin in JAK2V617F-positive MPNs.