Hematology and Coagulation
Yanhua Li, MD
UMass Memorial Medical Center, UMass Chan Medical School, Massachusetts, United States
Polycythemia Vera (PV) is a chronic myeloproliferative neoplasm with increased risk of thromboembolic events (TEs). To prevent TEs, therapeutic phlebotomy (TP) is crucial for maintaining target hematocrit (Hct). We present an 86-year-old female with JAK2-positive, high-risk PV who experienced recurrent acute pulmonary embolism (PE) 5 years ago. She has been on regular TP, rivaroxaban 20 mg and aspirin 81 mg. She was diagnosed with PV with JAK2V617 mutation 2 years ago. Hydroxyurea was initially administered but discontinued due to decreased platelets count. Rivaroxaban was also stopped. After failed TP attempts, she was transferred to the Emergency Room, admission 1 (A1), hospital day 0 (HD0), with body aches, headache, right chest pain, and Hct 53.2 (35-46)% with mean corpuscular volume (MCV) 71.3 (80-100)fL secondary to iron deficiency. Chest computed topographic angiography (CTA) revealed extensive PE.
On admission day, A1 HD0, Enoxaparin 1mg/kg sq q12hrs was initiated and later switched to rivaroxaban 15 mg PO daily on A1HD1. TP was attempted and failed, attributed to poor venous access, partially secondary to dehydration. She was advised to hydrate well. On A1HD2, multiple ultrasound-guided (US) TP attempts, including using normal saline filed needles, failed. The needle position was confirmed inside the lumen of the vessels by US, but no blood could be drawn, indicating an instant clot formation inside the needle.
On A1HD3, Unfractionated Heparin (UFH) IV was started with a target activated partial thromboplastin time (aPTT) 65-85 sec. Rivaroxaban was stopped. TP1 was successfully performed.
The next day, A1HD4, her Hct decreased to 45.2 % from 54%, suggesting hydration is one of the contributors to her Hct decrease, besides TP. Her initial chest pain resolved, O2 was weaned. She was discharged.
About 5 weeks later, she was re-admitted (A2) for TP failures, without complaints. On admission day (A2HD0), her Hct 48.4% (Target Hct is < 42%), aPTT was 32.9 sec. UFH IV was started with target aPTT 65-85 sec. After heparinization, TP2 and TP3 were performed successfully on A2HD1 and A2HD2 respectively. On A2HD3, she was discharged with Hct 41.3%, on Rivaroxaban.
A PV patient with iron-deficient indices and multiple TP failures was phlebotomized after heparinization. The failures of TP could be a sign of the patient’s hypercoagulable state in which her iron deficient indices may play a role. This is consistent with published study that iron-deficient indices increase cell-cell interaction causing an increase in whole-blood viscosity. Per literature search, there is no published heparinization use in resolving venous access for TP in PV cases with TP failures. This highlights clinical awareness of this condition (PV, iron deficiency and TP failures) and demonstrates that anticoagulation is an effective strategy for managing this condition.