Clinical Commander

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neuro.stroke-laa.v1

Large-Artery Atherosclerotic Stroke (TOAST LAA)

neurologyacutechronicadultacuteinpatientoutpatient
Start encounter →Print handoutPRODUCTION

Phase C wave-14 shard-3 neuro stroke-phenotype expansion (2026-05-15): authored at INTEGRATED tier — manifest file forward-declared (does not yet exist on disk; PRODUCTION promotion requires manifest + RxNav-validated terminology + lab-input LOINC). 8 phenotype severity_triggers span the LAA TOAST class: symptomatic carotid ≥50% / critical 70-99% / intracranial atherosclerosis (SAMMPRIS) / vertebrobasilar / aortic arch / CABG-related / CEA-vs-CAS (CREST) / APOL1-AA overlap. 5 setting playbooks span the full LAA journey: ed (acute confirmation + reperfusion coordination) → icu (post-revascularisation + hyperperfusion watch) → inpatient (mechanism workup + CEA/CAS prep + SAMMPRIS DAPT init) → outpatient (90-d / 12-mo clinic + DAPT taper + carotid surveillance) → home (adherence + BP log + symptom recognition). Schema-blocked downstream (depth bundle): calc.nascet_pct (NASCET % stenosis), calc.crest_score (CREST CEA-vs-CAS suitability), calc.sammpris_eligibility (intracranial atherosclerosis qualifying-event). Surfaced in depth bundle until clinical-tools-registry expands. Regimen axis encoded with 6 steps: high-intensity statin (lifelong) → aspirin baseline → SAMMPRIS DAPT × 90 d for ICAD → cilostazol refractory → COMPASS polyvascular → BP + glycemic + smoking cessation lifestyle bundle. Sibling differentiation: neuro.ischaemic-stroke.v1 (parent acute; reperfusion lives there), neuro.tia.v1 (LAA-mechanism TIA; shares CEA/CAS window), cardio.ascvd.chronic.v1 (whole-body ASCVD RF management).

Entry points (5)

  • symptom
    Cortical / borderzone infarct pattern suggesting LAA mechanism (AHA/ASA 2021 PMID 34024117)
    cortical_or_borderzone_infarct_pattern
  • imaging
    Carotid stenosis ≥50% ipsilateral on CTA/MRA/duplex (NASCET measurement; AHA/ASA 2021 Class I)
    carotid_stenosis_ge_50pct_ipsilateral
  • imaging
    Intracranial atherosclerosis on vessel-wall MRI or hi-res CTA (SAMMPRIS Chimowitz NEJM 2011 PMID 21507093)
    intracranial_atherosclerosis_on_vessel_wall_mri
  • imaging
    Complex aortic arch atheroma ≥4 mm or mobile component on TEE (Amarenco 1994; ARCH 2014)
    aortic_arch_atheroma_ge_4mm
  • history
    Recent CABG / vascular endovascular procedure → CABG-related atheroembolic stroke (AHA/ASA 2021)
    recent_cabg_or_endovascular_procedure

Required inputs (15)

  • agerequired
    demographic • used at CONTEXT
    Age stratifies CEA vs CAS choice (CREST — older patients benefit more from CEA; younger from CAS); affects bleed risk of intensive statin/DAPT (AHA/ASA 2021)
  • index_event_typerequired
    symptom • used at RISK_STRATIFICATION
    TIA vs minor stroke vs major stroke — qualifying event for SAMMPRIS / NASCET defines treatment window (≤14 d for CEA/CAS per AHA/ASA 2021 Class I)
  • symptom_onset_timerequired
    symptom • used at TREATMENT
    CEA/CAS within 14 d of symptomatic event maximises benefit per NASCET / pooled European Carotid Surgery Trial (AHA/ASA 2021 Class I)
  • sbprequired
    vital • used at TREATMENT
    Target BP <130/80 long-term per AHA/ASA 2021 + 2025 AHA/ACC HTN secondary prevention; avoid SBP <120 in critical bilateral carotid stenosis (perfusion pressure)
  • carotid_duplex_or_cta_neckrequired
    imaging • used at INITIAL_WORKUP
    NASCET measurement of ipsilateral carotid stenosis drives CEA/CAS decision (AHA/ASA 2021 Class I)
  • cta_or_mra_headrequired
    imaging • used at INITIAL_WORKUP
    Intracranial vessel patency for SAMMPRIS eligibility (Chimowitz NEJM 2011 PMID 21507093); vertebrobasilar atheroma detection
  • mri_brain_dwirequired
    imaging • used at INITIAL_WORKUP
    Confirms ischemic territory + borderzone pattern (perfusion failure phenotype) supporting LAA mechanism (AHA/ASA 2021)
  • tee_aortic_arch
    imaging • used at BRANCHING_WORKUP
    Identifies complex aortic arch atheroma ≥4 mm — under-recognised LAA source (Amarenco 1994; ARCH 2014)
  • ldlrequired
    lab • used at FOLLOWUP
    High-intensity statin target LDL <55 mg/dL post-LAA stroke (2026 ACC/AHA Lipid; SPARCL PMID 16899775); LDL >100 mandates intensification
  • hba1c
    lab • used at FOLLOWUP
    Glycemic control HbA1c <7% reduces atherosclerotic progression (ADA 2026; AHA/ASA 2021)
  • creatininerequired
    lab • used at CONTEXT
    eGFR for contrast CTA/CTP and SAMMPRIS DAPT bleed-risk assessment
  • smoking_statusrequired
    history • used at CONTEXT
    Active smoking accelerates atherosclerosis; cessation pharmacotherapy per AHA/ASA 2021 Class I
  • prior_cea_or_cas
    history • used at CONTEXT
    Prior carotid intervention reframes anatomy + restenosis surveillance pathway (AHA/ASA 2021)
  • apol1_overlap_aa
    history • used at CONTEXT
    APOL1 variant + African American ancestry — emerging signal for accelerated atherosclerosis + CKD-stroke overlap (research-grade)
  • current_antiplatelet_or_anticoagrequired
    medication • used at TREATMENT
    Existing antithrombotic on board drives DAPT initiation decision (SAMMPRIS DAPT × 90 d adds clopidogrel to aspirin); avoid triple therapy

12-phase flow (12)

  1. 1FRAME
    Ischemic stroke with LAA mechanism — carotid ≥50%, intracranial atherosclerosis, vertebrobasilar atheroma, aortic arch atheroma, or CABG-related atheroembolism (AHA/ASA 2021)
    advance: LAA mechanism flagged or being investigated
  2. 2ENTRY
    TOAST classification process — receives patient already routed from neuro.ischaemic-stroke.v1 with LAA suspicion based on infarct pattern + vessel imaging
    inputs: index_event_type
    advance: LAA pathway activated
  3. 3CONTEXT
    Capture vascular risks, smoking, lipids, glycemic status, prior interventions, current antithrombotic, renal function (AHA/ASA 2021)
    inputs: age, sbp, smoking_status, current_antiplatelet_or_anticoag, creatinine
    advance: Risk factor context captured
  4. 4RED_FLAGS
    Critical / preocclusive carotid (≥95% with poor collaterals); crescendo TIAs ipsilateral to stenosis; intracranial high-grade stenosis with recurrent events on aspirin → emergent intervention (AHA/ASA 2021 Class I)
    inputs: sbp
    advance: No immediate-intervention indication, or such indication acted upon
  5. 5INITIAL_WORKUP
    Carotid duplex + CTA/MRA head/neck within 24 h; MRI brain DWI for territorial confirmation; lipid panel + HbA1c + renal panel (AHA/ASA 2021 Class I)
    inputs: carotid_duplex_or_cta_neck, cta_or_mra_head, mri_brain_dwi
    actions: panel.renal, panel.lipid
    advance: Vessel + lipid + renal workup complete
  6. 6BRANCHING_WORKUP
    TEE for aortic arch atheroma if cryptogenic-LAA pattern (cortical + multi-territory without identified extracranial source) (Amarenco 1994); CABG-related atheroembolism workup if recent procedure; APOL1 in selected research contexts
    inputs: tee_aortic_arch
    advance: Source localised — carotid / intracranial / vertebrobasilar / aortic arch / CABG-related
  7. 7DIFFERENTIAL
    LAA sub-phenotype: symptomatic carotid ≥50% vs critical 70-99% vs intracranial MAD (Mod-Adv Disease) SAMMPRIS-eligible vs vertebrobasilar vs aortic arch vs CABG-related (AHA/ASA 2021; SAMMPRIS Chimowitz NEJM 2011)
    advance: LAA sub-phenotype assigned
  8. 8RISK_STRATIFICATION
    NIHSS for severity context; ABCD2 if TIA-spectrum; NASCET % stenosis for carotid intervention threshold; SAMMPRIS eligibility for intracranial atherosclerosis (AHA/ASA 2021 Class I)
    inputs: index_event_type
    advance: NASCET % + intervention candidacy documented
  9. 9TREATMENT
    High-intensity statin LDL <55 (SPARCL PMID 16899775); CEA within 14 d for symptomatic ≥50% carotid (NASCET; AHA/ASA 2021 Class I); CAS alternative per CREST (Brott NEJM 2010 PMID 20505173); SAMMPRIS DAPT aspirin + clopidogrel × 90 d for intracranial atherosclerosis (Chimowitz NEJM 2011 PMID 21507093); BP <130/80 (2025 AHA/ACC HTN); cilostazol for refractory ICAD; COMPASS rivaroxaban 2.5 BID + aspirin for stable atherosclerosis (Eikelboom NEJM 2017)
    inputs: symptom_onset_time, current_antiplatelet_or_anticoag
    advance: Phenotype-specific Rx initiated (statin + antithrombotic ± intervention plan)
  10. 10DISPOSITION
    Inpatient continuation of acute stroke care; vascular surgery referral for CEA/CAS; outpatient stroke clinic + vascular surgery follow-up (AHA/ASA 2021)
    advance: Disposition documented
  11. 11MONITORING
    Inpatient telemetry; carotid duplex post-CEA at 6 wk + 6 mo + annually; LFTs/CK on statin; bleed surveillance on DAPT (SAMMPRIS 90-d cap to limit bleed signal) (AHA/ASA 2021)
    advance: Monitoring plan documented
  12. 12FOLLOWUP
    Stroke clinic 7-14 d + 90 d + 12 mo: LDL <55, BP <130/80, HbA1c <7%, antithrombotic adherence, smoking cessation, carotid surveillance (AHA/ASA 2021)
    inputs: ldl, hba1c
    actions: panel.lipid
    advance: Secondary prevention bundle on board + carotid surveillance scheduled