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cardio.dvt.antiphospholipid-syndrome.v1PRODUCTION
cardio.dvt.antiphospholipid-syndrome.v1

Antiphospholipid syndrome (APS) DVT — warfarin preferred, DOAC avoided

cardiologyacuteadult
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11/12 authored

Canonical 12-phase frame with authored status for this dossier.

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Frame

Detailed

APS = autoimmune thrombophilia with recurrent thrombosis (venous + arterial) + pregnancy morbidity + persistent aPL; warfarin preferred (target INR 2-3 venous, 2.5-3.5 arterial/recurrent, 3-4 some triple-positive); DOAC INFERIOR (TRAPS terminated for harm); lifelong AC; CAPS = catastrophic multi-organ phenotype

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APS phenotype framed

Patient inputs (14)

LA is most thrombosis-specific aPL; functional assay (DRVVT + confirm) — must be confirmed at ≥12 wk to satisfy Sapporo/Sydney; cannot reliably interpret on warfarin or full-dose DOAC (mixing study workaround)

IgG and IgM medium-to-high titre (>40 GPL/MPL or >99th percentile) at ≥12 wk — Sapporo/Sydney lab criterion

IgG and IgM medium-to-high titre (>99th percentile) at ≥12 wk — Sapporo/Sydney lab criterion; "triple-positive" if all three classes (LA + aCL + anti-β2GPI) positive — highest recurrence risk

APS often presents in young adults (3rd-5th decade); pregnancy-morbidity criteria apply only to women of reproductive age

Women with APS face pregnancy management decisions (LMWH + ASA antepartum; hydroxychloroquine adjunct); reproductive planning is central

Prior arterial or venous thrombosis defines APS clinical criterion; first vs recurrent affects intensity of AC (target INR 2-3 vs 2.5-3.5 vs 3-4 per phenotype)

≥3 consecutive losses <10 wk, or ≥1 fetal death ≥10 wk, or severe preeclampsia/placental insufficiency — Sapporo/Sydney pregnancy criteria; informs reproductive plan

Secondary APS (most often associated with SLE, less commonly Sjögren / RA / scleroderma); affects multi-system surveillance

Cardinal symptom of proximal DVT

Initial confirmation of DVT location (proximal vs distal)

Baseline platelet for AC and APS-associated thrombocytopenia screen

Baseline coags; prolonged aPTT not correcting with mixing study supports LA; PT/INR baseline for warfarin titration

HAS-BLED for AC bleed risk; lifelong AC mandates bleed-risk vigilance

eGFR for LMWH dosing; renal involvement (APS nephropathy) screen

* = hard-required. Engine cannot meaningfully run until these are filled.

Severity triggers (4)

4 need judgement
  • informationallife_threateningcatastrophic_aps_caps_multi_organ_thrombosis
    CAPS — ≥3 organ thromboses ≤1 week with histopathological confirmation of small-vessel thrombosis (or strong clinical surrogate); life-threatening with ~37% mortality even with treatment
    Trigger could not be auto-evaluated — needs clinician judgement.
  • informationalseveredoac_inadvertently_started_in_known_aps
    Patient with established APS diagnosis found to be on rivaroxaban, apixaban, edoxaban, or dabigatran — must transition to warfarin immediately given TRAPS / ASTRO-APS evidence of harm
    Trigger could not be auto-evaluated — needs clinician judgement.
  • informationalseverepregnancy_planning_in_triple_positive_aps
    Triple-positive APS woman planning pregnancy — highest fetal/maternal risk requires pre-conception planning with LMWH + low-dose ASA antepartum + 6-wk postpartum LMWH; warfarin discontinuation at conception (teratogenic in 1st trimester)
    Trigger could not be auto-evaluated — needs clinician judgement.
  • informationalsevererecurrent_thrombosis_on_therapeutic_warfarin_inr_2-3
    New thrombotic event in APS patient with documented therapeutic INR 2-3 — must escalate intensity (INR 2.5-3.5 or 3-4) or add adjunct (low-dose ASA, hydroxychloroquine, or LMWH overlap)
    Trigger could not be auto-evaluated — needs clinician judgement.

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Recommended regimen

Antiphospholipid syndrome anticoagulation — WARFARIN preferred (INR target by phenotype), LMWH in pregnancy, DOAC INFERIOR and avoided (TRAPS, ASTRO-APS, EULAR 2019)
axis: aps_anticoagulation_warfarin_first_doac_avoided
Selected axis "Antiphospholipid syndrome anticoagulation — WARFARIN preferred (INR target by phenotype), LMWH in pregnancy, DOAC INFERIOR and avoided (TRAPS, ASTRO-APS, EULAR 2019)" by default fallback (first axis)
  • warfarin
    first line
    vitamin_k_antagonist
    5 mg PO daily; target INR 2-3 (first venous APS event), 2.5-3.5 (arterial APS or recurrent venous APS), 3-4 (selected triple-positive cases per expert opinion) • PO • daily lifelong
    triggers: aps_with_acute_dvt_after_lmwh_bridge, aps_arterial_event, aps_recurrent_venous_event
    TRAPS (Pengo Blood 2018 PMID 30196097) — warfarin SUPERIOR to rivaroxaban in triple-positive APS; EULAR 2019 — warfarin first-line; lifelong AC per APS clinical criterion
    rxcui 11289
  • enoxaparin
    first line
    lmwh
    1 mg/kg SC BID (reduce to 1 mg/kg SC daily if CrCl <30); overlap with warfarin until INR therapeutic for ≥2 consecutive days • SC • BID
    triggers: aps_acute_vte_initial_anticoagulation, aps_pregnancy, aps_warfarin_bridge
    ASH 2020 (PMID 33007077); ASH 2018 pregnancy (PMID 30482767) — LMWH first-line in pregnancy; standard initial AC overlap with warfarin (≥5 d + INR therapeutic ≥2 d)
    rxcui 67108
  • aspirin
    add on
    antiplatelet_cox1
    81 mg PO daily • PO • daily
    triggers: aps_arterial_event_secondary_prevention, aps_pregnancy_low_dose_asa_antepartum, aps_with_recurrent_thrombosis_on_warfarin
    EULAR 2019 — low-dose ASA add-on for arterial APS; antepartum low-dose ASA + LMWH for APS pregnancy improves fetal outcomes; potential benefit in recurrent thrombosis on therapeutic warfarin
    rxcui 243670
  • hydroxychloroquine
    add on
    antimalarial_immunomodulator
    200-400 mg PO daily (max 5 mg/kg/day actual body weight per AAO retinopathy guidance) • PO • daily
    triggers: aps_associated_with_sle, aps_recurrent_thrombosis_despite_warfarin_consider_adjunct
    EULAR 2019 — hydroxychloroquine adjunct in SLE-associated APS reduces thrombosis recurrence; observational data support adjunct in recurrent APS thrombosis on warfarin
    rxcui 5521
  • heparin
    first line
    unfractionated_heparin
    80 U/kg IV bolus + 18 U/kg/h targeting aPTT 1.5-2.5× (LA may falsely prolong aPTT — use anti-Xa assay if available) • IV • continuous
    triggers: aps_acute_severe_renal_impairment, aps_peri_procedural_bridge, aps_pe_with_hemodynamic_instability
    Reversibility for peri-procedural management; anti-Xa monitoring preferred when LA confounds aPTT (ACCP 2021)
    rxcui 235473
  • AVOID rivaroxaban
    contraindication substitute
    do_not_use
    AVOID • N/A • N/A
    triggers: aps_diagnosis
    TRAPS (Pengo Blood 2018 PMID 30196097) — trial terminated early for arterial harm in triple-positive APS; ISTH 2020 + EULAR 2019 advise against rivaroxaban in APS
  • AVOID apixaban in APS
    contraindication substitute
    do_not_use
    AVOID • N/A • N/A
    triggers: aps_arterial_phenotype, aps_triple_positive
    ASTRO-APS apixaban arm (Woller Blood Adv 2022) — terminated for harm in arterial APS; class effect concern; EULAR 2019
  • methylprednisolone
    comorbidity specific
    corticosteroid_iv
    CAPS: methylprednisolone 1 g IV daily × 3 d → taper • IV • daily
    triggers: catastrophic_aps_caps
    CAPS Registry — corticosteroids one of the four pillars (anticoagulation + corticosteroids + plasma exchange + IVIG ± rituximab/eculizumab) in CAPS; mortality benefit in observational data
    rxcui 6902
  • fentanyl
    add on
    opioid_analgesic
    25-100 µg IV q5-10 min titrate • IV • PRN
    triggers: aps_severe_phlegmasia_pain, caps_multiorgan_distress
    Pain control; CAPS multi-organ ischemia is severely painful; reduces sympathetic drive
    rxcui 4337

outpatient playbook — drug actions (4)

  1. 1. maintenance warfarin lifelong
    rxcui 11289
    INR target per phenotype • PO • daily lifelong
    trigger: APS
    EULAR 2019; TRAPS PMID 30196097
  2. 2. switch to LMWH if pregnancy
    rxcui 67108
    enoxaparin 1 mg/kg SC BID antepartum + 6 wk postpartum + low-dose ASA antepartum • SC + PO • BID
    trigger: Pregnancy
    ASH 2018 pregnancy; EULAR 2019
  3. 3. hydroxychloroquine adjunct if SLE-associated or recurrent thrombosis
    rxcui 5521
    200-400 mg PO daily • PO • daily
    trigger: Secondary APS or recurrent thrombosis on warfarin
    EULAR 2019
  4. 4. statin for cardiovascular risk reduction (and pleiotropic anti-thrombotic effect debated)
    rxcui 83367
    Atorvastatin 20-80 mg PO daily • PO • daily
    trigger: ASCVD risk + APS
    AHA ASCVD prevention; pleiotropic effects in APS observational

Auto-drafted A&P note

outpatient

Subjective

- Possible entry pathways: Unilateral leg swelling/pain with prior APS diagnosis OR strong APS suspicion (recurrent VTE, arterial + venous events, pregnancy morbidity, autoimmune disease — particularly SLE); Unprovoked VTE in patient with ≥3 consecutive miscarriages <10 wk OR ≥1 fetal death ≥10 wk OR severe preeclampsia/placental insufficiency — Sapporo/Sydney pregnancy-morbidity criteria; Patient with both prior arterial event (stroke, MI, TIA) AND venous event — APS until proven otherwise.

Objective

- No vitals, labs, or imaging entered for this encounter.

Assessment

**Antiphospholipid syndrome (APS) DVT — warfarin preferred, DOAC avoided** (cardio.dvt.antiphospholipid-syndrome.v1).
Scope: APS = autoimmune thrombophilia with recurrent thrombosis (venous + arterial) + pregnancy morbidity + persistent aPL; warfarin preferred (target INR 2-3 venous, 2.5-3.5 arterial/recurrent, 3-4 some triple-positive); DOAC INFERIOR (TRAPS terminated for harm); lifelong AC; CAPS = catastrophic multi-organ phenotype

No severity triggers fired against current inputs.

Plan

Regimen axis: **Antiphospholipid syndrome anticoagulation — WARFARIN preferred (INR target by phenotype), LMWH in pregnancy, DOAC INFERIOR and avoided (TRAPS, ASTRO-APS, EULAR 2019)**.
1. warfarin 5 mg PO daily; target INR 2-3 (first venous APS event), 2.5-3.5 (arterial APS or recurrent venous APS), 3-4 (selected triple-positive cases per expert opinion) PO daily lifelong (vitamin_k_antagonist, first line) — TRAPS (Pengo Blood 2018 PMID 30196097) — warfarin SUPERIOR to rivaroxaban in triple-positive APS; EULAR 2019 — warfarin first-line; lifelong AC per APS clinical criterion
2. enoxaparin 1 mg/kg SC BID (reduce to 1 mg/kg SC daily if CrCl <30); overlap with warfarin until INR therapeutic for ≥2 consecutive days SC BID (lmwh, first line) — ASH 2020 (PMID 33007077); ASH 2018 pregnancy (PMID 30482767) — LMWH first-line in pregnancy; standard initial AC overlap with warfarin (≥5 d + INR therapeutic ≥2 d)
3. aspirin 81 mg PO daily PO daily (antiplatelet_cox1, add on) — EULAR 2019 — low-dose ASA add-on for arterial APS; antepartum low-dose ASA + LMWH for APS pregnancy improves fetal outcomes; potential benefit in recurrent thrombosis on therapeutic warfarin
4. hydroxychloroquine 200-400 mg PO daily (max 5 mg/kg/day actual body weight per AAO retinopathy guidance) PO daily (antimalarial_immunomodulator, add on) — EULAR 2019 — hydroxychloroquine adjunct in SLE-associated APS reduces thrombosis recurrence; observational data support adjunct in recurrent APS thrombosis on warfarin
5. heparin 80 U/kg IV bolus + 18 U/kg/h targeting aPTT 1.5-2.5× (LA may falsely prolong aPTT — use anti-Xa assay if available) IV continuous (unfractionated_heparin, first line) — Reversibility for peri-procedural management; anti-Xa monitoring preferred when LA confounds aPTT (ACCP 2021)
6. AVOID rivaroxaban AVOID N/A N/A (do_not_use, contraindication substitute) — TRAPS (Pengo Blood 2018 PMID 30196097) — trial terminated early for arterial harm in triple-positive APS; ISTH 2020 + EULAR 2019 advise against rivaroxaban in APS
7. AVOID apixaban in APS AVOID N/A N/A (do_not_use, contraindication substitute) — ASTRO-APS apixaban arm (Woller Blood Adv 2022) — terminated for harm in arterial APS; class effect concern; EULAR 2019
8. methylprednisolone CAPS: methylprednisolone 1 g IV daily × 3 d → taper IV daily (corticosteroid_iv, comorbidity specific) — CAPS Registry — corticosteroids one of the four pillars (anticoagulation + corticosteroids + plasma exchange + IVIG ± rituximab/eculizumab) in CAPS; mortality benefit in observational data
9. fentanyl 25-100 µg IV q5-10 min titrate IV PRN (opioid_analgesic, add on) — Pain control; CAPS multi-organ ischemia is severely painful; reduces sympathetic drive

Setting playbook (outpatient) — Lifelong AC management with annual reassessment; reproductive planning for women; co-management of associated SLE / autoimmune disease; cardiovascular risk reduction; CAPS recurrence-prevention
10. maintenance warfarin lifelong INR target per phenotype PO daily lifelong — APS (EULAR 2019; TRAPS PMID 30196097)
11. switch to LMWH if pregnancy enoxaparin 1 mg/kg SC BID antepartum + 6 wk postpartum + low-dose ASA antepartum SC + PO BID — Pregnancy (ASH 2018 pregnancy; EULAR 2019)
12. hydroxychloroquine adjunct if SLE-associated or recurrent thrombosis 200-400 mg PO daily PO daily — Secondary APS or recurrent thrombosis on warfarin (EULAR 2019)
13. statin for cardiovascular risk reduction (and pleiotropic anti-thrombotic effect debated) Atorvastatin 20-80 mg PO daily PO daily — ASCVD risk + APS (AHA ASCVD prevention; pleiotropic effects in APS observational)

Non-pharmacologic actions:
- Estrogen/OCP avoidance lifelong
- Smoking cessation
- Cardiovascular risk modification
- Pre-procedure AC management plan documented
- Patient carries APS card
- EHR DOAC-avoidance flag annually verified

AVOID / contraindication checks:
- Doac_avoid_in_aps_TRAPS_terminated_for_harm (TRAPS PMID 30196097)
- Apixaban_avoid_in_arterial_aps_ASTRO_APS_terminated (Woller 2022)
- Warfarin_avoid_in_pregnancy_use_lmwh (ASH 2018 pregnancy)
- Warfarin_avoid_active_bleeding (FDA label)
- Lmwh_renal_dose_reduction_below_egfr_30 (FDA label)
- La_interferes_with_aptt_monitoring_use_anti_xa_for_ufh (ACCP 2021)
- Aps_lifelong_anticoagulation_no_taper_no_stop (EULAR 2019)
- Decision:aps_first_venous_event_warfarin_inr_2 3_lifelong (EULAR 2019)
- Decision:aps_arterial_or_recurrent_venous_warfarin_inr_2.5 3.5_lifelong (EULAR 2019)
- Decision:triple_positive_aps_consider_inr_3 4_per_expert_opinion (Pengo TRAPS commentary)
- Decision:aps_pregnancy_lmwh_plus_low_dose_asa_antepartum_plus_6wk_postpartum (ASH 2018 pregnancy / EULAR 2019)
- Decision:caps_multi_modality_anticoagulation_plus_steroids_plus_pex_plus_ivig (CAPS Registry)
- Decision:ehr_flag_doac_avoidance_in_aps_patient (safety operational)

Monitoring

Regimen monitoring:
- inr weekly during warfarin initiation then q2-4 weeks maintenance (ACCP 2021)
- cbc creatinine quarterly during lifelong AC (FDA labels)
- pts villalta at 3 6 12mo (Kahn Lancet 2014)
- annual AC continuation decision documented lifelong in APS (EULAR 2019)
- aPL repeat at 12wk to satisfy persistence criterion (Sapporo/Sydney)
- sle surveillance if secondary APS with rheumatology (EULAR 2019)
- pre pregnancy LMWH dose planning and warfarin discontinuation at conception (ASH 2018 pregnancy)
- pre procedure AC bridging plan documented lifelong (ACCP 2021)

Setting (outpatient) monitoring:
- Quarterly INR
- Annual CBC + creatinine + lipid + A1c
- Annual HAS-BLED
- Annual reproductive counseling for women
- Annual rheumatology if secondary APS

Follow-up plan: Hematology + rheumatology co-management; reproductive planning for women (LMWH + low-dose ASA antepartum + 6-wk postpartum; hydroxychloroquine adjunct); estrogen avoidance lifelong; cardiovascular risk modification; APS patient card for emergency providers; no DOAC prescription warning in EHR
- Close-out criterion: lifelong AC + reproductive plan + interdisciplinary follow-up + EHR DOAC-avoidance flag documented

Monitoring phase: INR weekly during warfarin titration → q2-4 wk maintenance; CBC + creatinine quarterly; bleed surveillance; PTS Villalta at 3/6/12 mo; annual reassessment confirms lifelong AC continuation; SLE/autoimmune surveillance if secondary APS

Disposition

Current setting: outpatient — Lifelong AC management with annual reassessment; reproductive planning for women; co-management of associated SLE / autoimmune disease; cardiovascular risk reduction; CAPS recurrence-prevention

Disposition criteria:
- Lifelong continuation; cross-reference with chronic-AC clinic + rheumatology

Escalation triggers (move to higher acuity):
- Recurrent VTE on therapeutic INR → escalate intensity; consider hydroxychloroquine adjunct or LMWH switch
- Pregnancy → switch to LMWH + ASA
- Major bleed → reverse, hold, reassess AC intensity (rarely stop)
- CAPS features → ED + ICU multi-modality

Earlier-Return Triggers

Return-precaution thresholds (watch for):
- [LIFE_THREATENING] CAPS — ≥3 organ thromboses ≤1 week with histopathological confirmation of small-vessel thrombosis (or strong clinical surrogate); life-threatening with ~37% mortality even with treatment
- [SEVERE] Patient with established APS diagnosis found to be on rivaroxaban, apixaban, edoxaban, or dabigatran — must transition to warfarin immediately given TRAPS / ASTRO-APS evidence of harm
- [SEVERE] Triple-positive APS woman planning pregnancy — highest fetal/maternal risk requires pre-conception planning with LMWH + low-dose ASA antepartum + 6-wk postpartum LMWH; warfarin discontinuation at conception (teratogenic in 1st trimester)

Citations

- EULAR 2019 APS management + ASH 2020 VTE Treatment + ASH 2018 thrombophilia testing + ASH 2018 VTE in Pregnancy + ACCP/CHEST 2021 + 2023 ACR/EULAR APS classification criteria [PMID:30196097](https://pubmed.ncbi.nlm.nih.gov/30196097/)
- Cited evidence (PMID 27932287) [PMID:27932287](https://pubmed.ncbi.nlm.nih.gov/27932287/)
- Cited evidence (PMID 29562136) [PMID:29562136](https://pubmed.ncbi.nlm.nih.gov/29562136/)
- Cited evidence (PMID 30482764) [PMID:30482764](https://pubmed.ncbi.nlm.nih.gov/30482764/)
- Cited evidence (PMID 30482767) [PMID:30482767](https://pubmed.ncbi.nlm.nih.gov/30482767/)

Last reconciled with current guidelines: 2026-05-15.
References
  • EULAR 2019 APS management + ASH 2020 VTE Treatment + ASH 2018 thrombophilia testing + ASH 2018 VTE in Pregnancy + ACCP/CHEST 2021 + 2023 ACR/EULAR APS classification criteria — PMID:30196097
  • Cited evidence (PMID 27932287) — PMID:27932287
  • Cited evidence (PMID 29562136) — PMID:29562136
  • Cited evidence (PMID 30482764) — PMID:30482764
  • Cited evidence (PMID 30482767) — PMID:30482767