Draft Clinical Pathway Only For internal review and discussion. Not an approved policy document.
PATHWAY ED Chest Pain Assessment Flow
Step 1 · Arrival
Adult patient presents with chest pain / suspected ACS
Triage immediately. Assign ATS Category 2 or 3.
Step 2 · Immediate Assessment (within 10 min)
Simultaneous Investigations
  • 12-lead ECG - interpret immediately, repeat if any symptom change
  • IV access · FBC, UEC, i-STAT cTnI (0h), BSL, lipids, coags, group & hold
  • Continuous cardiac monitoring · SpO₂ · vital signs (BP both arms if dissection suspected)
  • Chest X-ray (PA or AP)
  • Brief focused history: onset, character, radiation, severity
Step 3 · Decision
STEMI / Haemodynamic Instability?
ST elevation ≥1 mm (limb) / ≥2 mm (chest) · New LBBB · Cardiogenic shock · Cardiac arrest · Suspected aortic dissection
YES — STEMI
⚡ STEMI Pathway — PAH & Ipswich >60 min away
Fibrinolysis First → Transfer to PAH
Primary PCI not achievable within 120 min → Lyse if no contraindications
  • Aspirin 300 mg PO + Clopidogrel 300 mg PO if <75 yr, or 75 mg PO if ≥75 yr, stat
  • Screen contraindications - see Fibrinolysis tab
  • Tenecteplase (TNKase) IV bolus - weight-based dosing
  • Heparin IV per fibrinolysis protocol
  • Target door-to-needle <30 minutes
  • Notify QAS + PAH Cath Lab
  • Transfer to PAH: rescue PCI if failed reperfusion, or routine angio 3-24 h if successful
Aortic dissection suspected? Do NOT give lysis. Immediate transfer to PAH for CT aortogram and surgical assessment.
NO
Standard Pathway
Proceed to HEART Score
Calculate HEART Score using initial ECG, history, age, risk factors, and 0h cTnI result.
Step 4 · Risk Stratification
Calculate HEART Score (0-10)
H - History | E - ECG | A - Age | R - Risk Factors | T - cTnI (local threshold 0.04 ug/L) · See HEART Calculator tab.
Step 5 · Serial Troponins
i-STAT cTnI: 0h · 3h · 6h
All HEART 4-10 patients require serial sampling. Low HEART + 0h negative: may discharge after 3h if delta <0.02 ng/mL and clinically well.
Step 6 · Disposition
HEART Score + Troponin Result → Disposition
Low Risk
HEART 0-3
MACE risk <2%
  • Two negative troponins
  • No ECG changes
  • Discharge from ED
  • GP follow-up 72 h
  • Discharge letter
  • Safety-netting
  • Consider outpatient ETT
Intermediate
HEART 4-6
MACE risk 2-20%
  • Serial troponins mandatory
  • Cardiology review
  • Admit or extended obs
  • Consider ETT or CTA
  • Refer to Ipswich Hospital
High Risk
HEART 7-10
MACE risk >20%
  • Urgent cardiology consult
  • Admit under cardiology
  • Transfer to Ipswich Hospital
  • STEMI/unstable → PAH via fibrinolysis pathway
STEMI PROTOCOLFibrinolysis Pathway - Tenecteplase (TNKase)
When to use this pathwayLaidley Hospital is >60 minutes from both Ipswich Hospital and Princess Alexandra Hospital (PAH). When total ischaemic time from first medical contact to primary PCI would exceed 120 minutes, fibrinolysis is the recommended reperfusion strategy. Target door-to-needle <30 minutes.
Reperfusion decision algorithmSTEMI confirmed → Can PAH PCI be achieved within 120 min of first medical contact? No (Laidley context) → Fibrinolysis indicated if no contraindications → Give TNKase → Transfer to PAH for rescue PCI (if failed) or routine angiography (3-24 h if successful).
STEP 1 — Screen Absolute Contraindications (tick to confirm ABSENT)
STEP 2 — Note Relative Contraindications (senior clinician decision)
STEP 3 — Tenecteplase (TNKase) Weight-Based Dosing
Patient WeightTNKase DoseVolume (5 mg/mL reconstituted)
<60 kg30 mg6 mL IV bolus over 5-10 sec
60-69 kg35 mg7 mL IV bolus over 5-10 sec
70-79 kg40 mg8 mL IV bolus over 5-10 sec
80-89 kg45 mg9 mL IV bolus over 5-10 sec
≥90 kg50 mg (maximum)10 mL IV bolus over 5-10 sec
Age ≥75 yearsUse Clopidogrel 75 mg with no loading dose. TNKase dose is unchanged, but discuss with the senior clinician if bleeding risk is high.
STEP 4 — Adjunct Antiplatelet & Anticoagulant Therapy
DrugDoseNotes
Aspirin300 mg PO stat, then 100 mg dailyGive immediately. Chew or crush if possible for faster absorption.
Clopidogrel300 mg PO if <75 yr; 75 mg PO if ≥75 yrDo NOT use Ticagrelor or Prasugrel pre-fibrinolysis.
Unfractionated Heparin (UFH)60 units/kg IV bolus (max 4,000 units), then 12 units/kg/hr (max 1,000 units/hr)Start with TNKase. Adjust to aPTT 50-75 sec. Continue for minimum 48 h or until angiography.
GTN0.4 mg SL if SBP >100 mmHg and no RV infarctAvoid if hypotensive or RV infarction suspected.
Morphine2-4 mg IV titrated for painUse cautiously. Adequate analgesia remains important.
OxygenOnly if SpO₂ <94%Routine O₂ not recommended in normoxic STEMI patients.
STEP 5 — Assess Reperfusion at 60-90 minutes post-TNKase
Signs of successful reperfusion≥50% resolution of ST elevation in the lead with maximal ST elevation · Reperfusion arrhythmia · Relief of chest pain · Peak troponin earlier than expected
Reperfusion StatusAction
✓ Successful reperfusionTransfer to PAH for routine coronary angiography within 3-24 hours.
✗ Failed reperfusion (<50% ST resolution at 90 min)Rescue PCI required. Call QAS immediately for urgent transfer to PAH.
TOOLHEART Score Calculator
i-STAT cTnI referenceLaidley local decision threshold = 0.04 ug/L. Manufacturer 99th pct URL = 0.08 ug/L.
HEART Score
0/10
Low Risk
  • MACE risk <2%
  • Serial troponins: 0h and 3h
  • Both negative + clinically well: discharge
  • GP follow-up within 72 hours
  • Safety-netting counselling documented
  • Consider outpatient exercise stress test
PROTOCOLSerial i-STAT cTnI Protocol
Assay: Abbott i-STAT cTnI (conventional)Significant delta = rise ≥0.02 ng/mL between samples. A single negative troponin does NOT exclude ACS in intermediate or high-risk patients.
Time Pointi-STAT cTnI ThresholdInterpretation & Action
0h (Arrival)<0.04 ug/L = Negative
0.04-0.12 ug/L = 1-3× local threshold
>0.12 ug/L = >3× local threshold
Baseline. Informs HEART Troponin score. Do not discharge on single 0h result alone.
3h SampleDelta <0.02 ug/L = No significant riseHEART 0-3 + delta <0.02 ug/L + clinically well: safe discharge. Delta ≥0.02 ug/L or result ≥0.04 ug/L: treat as ACS.
6h SampleDelta <0.02 ug/L = No significant riseMandatory for HEART 4-10 and clinical uncertainty.
⚡ Bedside Delta Calculator — i-STAT cTnI (ug/L)
REFERRALTransfer and Referral Pathways
Geographic context — Laidley HospitalBoth Ipswich Hospital and Princess Alexandra Hospital (PAH) are >60 minutes from Laidley. For STEMI, fibrinolysis is first-line reperfusion.
🏥 Ipswich Hospital — Tertiary Referral
Indications:
  • HEART Score 4-10 - inpatient workup
  • Cardiology review required
  • Stress testing
  • CT Coronary Angiogram
  • NSTEMI / UA requiring inpatient management

Process:
  • Contact Ipswich ED Consultant on call
  • Document HEART score, troponins, ECG findings, and treatment
  • Arrange transport as clinically indicated
🚨 Princess Alexandra Hospital — STEMI / Intervention
Indications:
  • Post-fibrinolysis: all STEMI patients
  • Suspected aortic dissection
  • Haemodynamically unstable ACS
  • Cardiac arrest (post-ROSC)
  • Requires PCI or cardiac surgery

Process:
  • Call QAS for emergency transfer
  • Notify PAH Cath Lab
  • Transfer documentation: ECG, drug chart, vitals trend, lysis time
DISCHARGESafe Discharge Criteria
All criteria must be metIf any criterion cannot be confirmed, senior clinician review is required prior to discharge.
#CriterionDetails
1HEART Score 0-3Low risk confirmed. All five components scored and documented.
2Negative serial troponinsTwo negative i-STAT cTnI (<0.04 ug/L) at 0h and 3h (or 6h), delta <0.02 ug/L.
3No dynamic ECG changesSerial ECGs during observation - no new ST/T changes.
4Symptoms resolved or explainedSymptoms resolved OR clear non-cardiac cause identified.
5Clinically well and stableHaemodynamically stable. No ongoing chest pain.
6No high-risk featuresNo recent PCI/CABG, severe LVD, cocaine use, or other high-risk features.
7GP follow-up arrangedFollow-up within 72 hours confirmed.
8Safety-netting documentedPatient advised to return if pain recurs/worsens or new symptoms develop.
GOVERNANCEDocument Control & References
FieldDetail
AuthorDr Ameen Shaikh, Senior Medical Officer, Laidley Hospital Emergency Department
Document OwnerSenior Medical Officer, Laidley Hospital Emergency Department
Version1.2 - corrected clopidogrel dosing for age ≥75 years to 75 mg consistently
Effective DateApril 2026
Review DateApril 2027
Troponin AssayAbbott i-STAT cTnI (conventional) · Local threshold: 0.04 ug/L · Serial: 0h/3h/6h · Delta: ≥0.02 ug/L
Risk ToolHEART Score - validated for ED chest pain risk stratification