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cardio.dvt.jak2-mpn-related.v1

DVT in JAK2-V617F-positive myeloproliferative neoplasm (PV / ET / PMF)

cardiologyacuteadultacuteinpatienttransitionoutpatient
Start encounter →Print handoutPRODUCTION

Phase E variant of cardio.dvt.core.v1 — narrowed to thrombosis in JAK2-V617F-positive Philadelphia-negative myeloproliferative neoplasms (PV / ET / PMF). Inherits diagnostic arc from parent via routing; specializes for the cytoreduction-anchored, phlebotomy-anchored, low-dose-ASA-anchored, JAK2-allele-burden-monitored long-term plan. Manifest pointer reuses cardio.dvt.core.v1 manifest. Design-brief pointer reuses parent (JAK2-MPN-specific differences documented inline). Distinguishing features vs generic DVT: thrombosis is the leading cause of death in MPN; JAK2-V617F testing mandatory in young / middle-aged splanchnic vein thrombosis even with normal CBC; CYTOREDUCTION (HU first-line; interferon for young / pregnancy / HU-intolerance; ruxolitinib for HU-refractory PV per RESPONSE PMID 25629741) plus PHLEBOTOMY (Hct < 45% men / < 42% women per CYTO-PV PMID 23300175) plus LOW-DOSE ASA 81 mg daily (per ECLAP PMID 14702426) define the MPN-specific arc; DOACs acceptable per Barbui Blood Adv 2021 PMID 33591542; warfarin preferred for concurrent triple-positive APS (TRAPS PMID 30002145) or splanchnic VT with hepatic instability; bleeding paradox in extreme thrombocytosis (platelets > 1500 — acquired vWS) demands holding ASA until cytoreduction lowers platelets. AC duration: ≥ 3 mo for provoked-by-MPN, indefinite for splanchnic / recurrent / persistent high risk. Status INTEGRATED. Authored 2026-05-15 by shard-06-cardio-acute as JAK2-V617F-positive MPN-related DVT variant.

Entry points (4)

  • symptom
    Unilateral leg swelling in patient with aquagenic pruritus, erythromelalgia, splenomegaly, or unexplained polycythemia / thrombocytosis — suspect underlying MPN
    unilateral_leg_swelling_with_erythromelalgia_or_pruritus
  • history
    Splanchnic vein thrombosis (Budd-Chiari, portal, mesenteric, splenic) or cerebral venous sinus thrombosis as index event — JAK2-V617F testing mandatory even with normal CBC
    splanchnic_vein_thrombosis_or_unusual_site
  • lab_abnormality
    CBC at presentation with Hb > 16.5 (men) / > 16.0 (women), platelets > 450 × 10⁹/L, or WBC > 11 — order JAK2-V617F PCR
    cbc_with_polycythemia_thrombocytosis_or_leukocytosis
  • history
    Recurrent VTE on AC in patient with established JAK2-positive MPN — escalate to indefinite AC + cytoreduction optimization
    recurrent_vte_with_known_jak2_mpn

Required inputs (11)

  • agerequired
    demographic • used at CONTEXT
    Younger patients (< 60) with JAK2-positive PV/ET have lower thrombosis risk per IPSET-thrombosis; age > 60 plus prior thrombosis defines high-risk ET requiring cytoreduction
  • sexrequired
    demographic • used at CONTEXT
    Hematocrit target differs (men < 45%, women < 42%); JAK2-positive women on combined OCP have multiplicative VTE risk
  • mpn_subtype_historyrequired
    history • used at CONTEXT
    PV vs ET vs PMF drives phlebotomy strategy, expected blast risk, and cytoreduction choice (hydroxyurea vs interferon vs ruxolitinib)
  • leg_swellingrequired
    symptom • used at ENTRY
    Cardinal symptom of proximal DVT
  • compression_usrequired
    imaging • used at INITIAL_WORKUP
    Initial confirmation of DVT location (proximal vs distal)
  • cbc_with_smearrequired
    lab • used at INITIAL_WORKUP
    Polycythemia + thrombocytosis + leukocytosis pattern; smear shows giant platelets, immature granulocytes, dacrocytes (PMF); platelets > 1500 raise bleeding-paradox concern (acquired vWS)
  • jak2_v617f_pcrrequired
    lab • used at BRANCHING_WORKUP
    JAK2-V617F PCR (allele burden quantitation if available); first-line; if negative pursue JAK2 exon 12 in PV phenotype, CALR + MPL in ET / PMF phenotype
  • erythropoietin_levelrequired
    lab • used at BRANCHING_WORKUP
    Suppressed EPO supports primary polycythemia (PV) over secondary causes (hypoxia, EPO-secreting tumor)
  • creatininerequired
    lab • used at TREATMENT
    eGFR for DOAC dosing and contrast for any imaging
  • lft_panelrequired
    lab • used at INITIAL_WORKUP
    Hepatic function for splanchnic vein thrombosis evaluation; PMF can drive extramedullary hematopoiesis with hepatosplenomegaly
  • bleed_riskrequired
    history • used at RED_FLAGS
    HAS-BLED + GI bleed history + acquired vWS in extreme thrombocytosis drives AC + ASA combination decision

12-phase flow (11)

  1. 1FRAME
    JAK2-V617F-positive MPN = clonal stem-cell disorder with thrombosis as leading cause of morbidity/mortality; venous (DVT / PE / splanchnic / CVST) + arterial (stroke / MI). Acute AC matches parent; AC duration + cytoreduction + hematocrit target + low-dose ASA define the MPN-specific arc
    inputs: leg_swelling
    advance: JAK2-MPN phenotype framed
  2. 2ENTRY
    Wells DVT score + compression US; document MPN subtype, JAK2 status (or order JAK2-V617F if not yet done), splenomegaly, prior thrombotic events, current cytoreduction
    inputs: mpn_subtype_history, age
    advance: pretest probability + MPN context documented
  3. 3CONTEXT
    Allergies; OCP / hormone use; pregnancy plans; current cytoreduction (hydroxyurea / interferon / ruxolitinib); last phlebotomy; baseline Hct trajectory; family history; prior splanchnic vein thrombosis
    inputs: sex, mpn_subtype_history
    advance: context complete
  4. 4RED_FLAGS
    Concurrent PE; phlegmasia; absolute AC contraindication; ICH; acquired vWS with platelets > 1500 (bleeding paradox); splanchnic vein thrombosis with hepatic decompensation; concurrent triple-positive APS
    inputs: bleed_risk
    actions: pe_full, thrombocytopenia
    advance: critical features screened
  5. 5INITIAL_WORKUP
    Compression US (proximal vs distal); CBC with smear + reticulocyte count; BMP; LFTs; LDH; uric acid; coagulation panel; D-dimer if pretest probability borderline; troponin + BNP if PE confirmed
    inputs: compression_us, cbc_with_smear, creatinine, lft_panel
    actions: panel.cardiac, panel.renal, panel.coag
    advance: imaging confirms DVT and CBC pattern documented
  6. 6BRANCHING_WORKUP
    JAK2-V617F PCR (preferred allele-burden quantitation); if negative pursue JAK2 exon 12 (PV phenotype) or CALR + MPL (ET / PMF phenotype); EPO; ferritin; bone marrow biopsy with reticulin staining for definitive WHO 2022 MPN classification; thrombophilia panel sent BEFORE first AC dose if practical (DOACs interfere with lupus anticoagulant + protein C/S/AT); imaging of splanchnic vasculature if clinical suspicion
    inputs: jak2_v617f_pcr, erythropoietin_level
    advance: MPN subtype confirmed / pending
  7. 7RISK_STRATIFICATION
    Wells DVT, HAS-BLED, eGFR, IPSET-thrombosis (ET), ELN risk for PV / PMF; integrate MPN subtype + JAK2 allele burden + thrombosis history + cytoreduction status into AC duration plan; high-risk MPN VTE → indefinite AC + cytoreduction; splanchnic vein thrombosis = indefinite AC by default
    inputs: bleed_risk
    actions: calc.wells_dvt, calc.has_bled
    advance: AC duration + cytoreduction plan documented
  8. 8TREATMENT
    Acute AC: DOAC first-line for MPN VTE per Barbui 2021 (apixaban 10/7/5 or rivaroxaban 15/21/20 or edoxaban after LMWH bridge); WARFARIN preferred if triple-positive APS overlap or splanchnic vein thrombosis with hepatic instability; LOW-DOSE ASPIRIN 81 mg daily ADDED for PV and ET if no extreme thrombocytosis; PHLEBOTOMY for PV target Hct < 45% (men) / < 42% (women) per CYTO-PV; CYTOREDUCTION mandatory — hydroxyurea first-line, pegylated interferon for younger patients or pregnancy planning, ruxolitinib for HU-refractory PV
    inputs: creatinine, bleed_risk
    advance: acute AC + cytoreduction + Hct target plan documented
  9. 9DISPOSITION
    Outpatient hematology + AC clinic for uncomplicated proximal DVT in stable JAK2-MPN; admit if concurrent PE, splanchnic vein thrombosis with hepatic dysfunction, phlegmasia, extreme thrombocytosis with bleeding diathesis, or new MPN diagnosis requiring rapid cytoreduction
    advance: disposition documented
  10. 10MONITORING
    CBC weekly during cytoreduction titration then monthly; phlebotomy schedule for PV to maintain Hct target; JAK2 allele burden q6–12 mo to track disease modification; CBC + creatinine + LFTs at 4 weeks then quarterly during indefinite AC; bleed surveillance; PTS Villalta at 3 / 6 / 12 mo; annual reassessment of AC continuation + cytoreduction
    actions: panel.cardiac
    advance: monitoring schedule documented
  11. 11FOLLOWUP
    Long-term hematology + thrombosis clinic co-management; annual bone marrow if disease progression suspected (PV / ET → PMF / leukemia transformation); pregnancy planning (interferon + LMWH preferred over hydroxyurea + DOAC / warfarin); cardiovascular risk factor optimisation; education on splenic infarct + erythromelalgia + pruritus + transformation symptoms
    advance: long-term plan and disease-progression surveillance documented