CHEST PAIN50 General Medical Emergencies
(ii) Give unfractionated (UF) heparin i.v. bolus 60–70 units/kg
(maximum 5000 units), followed by an infusion at 12–15 units/
kg/h (maximum 1000 units/h)
(a) UF heparin may be preferred in hospitals likely to offer
coronary angioplasty (PCI) within 24–36 h of symptom
onset, so check your local policy
(b) titrate the UF heparin infusion to an activated partial
thromboplastin time (aPTT) of 50–70 s by 6 h post infusion.
4 Admit all patients.
The final diagnosis of NSTEMI (rise in cardiac troponin biomarker), UA (no
rise in troponin or cardiac biomarker) or non-cardiac chest pain (normal
cardiac biomarkers, normal ECGs, normal stress test) takes time to establish.
(i) Admit patients with ‘high-risk’ features directly to the coronary
care unit (CCU). This includes any one or more of:
(a) elevated troponin on arrival blood test, repetitive or
prolonged chest pain over 10 min, diabetic patient or chronic
kidney disease patient with estimated glomerular filtration
rate of <60 mL/min and typical symptoms of ACS, associated
syncope, symptoms or signs of heart failure (see p. 75), signs
of new mitral incompetence (pansystolic murmur), PCI in
the last 6 months or prior revascularization (coronary artery
bypass graft [CABG]), haemodynamic instability or ECG
changes.
(ii) Admit patients with ‘intermediate-risk’ features under the
medical team, possibly to a shared chest pain assessment unit
(CPAU). These include any one or more of:
(a) chest pain or discomfort within the past 48 h occurring
at rest, or that was repetitive or prolonged (but currently
resolved), age over 65 years, two or more risk factors
of hypertension, family history, active smoking or
hyperlipidaemia, and diabetic patient or chronic kidney
disease patient with estimated glomerular filtration rate of
<60 mL/min and atypical symptoms of ACS
(b) lack of CCU beds may necessitate that all diabetic or chronic
renal impairment patients are treated as intermediate-risk
and are admitted to a general ward (rather than to CCU as
high-risk if they have typical symptoms of ACS)
(c) repeat the ECG and troponin at 6–8 h post arrival in the ED
(d) admit the patient to CCU if chest pain recurs, the ECG
changes, or a repeat cardiac troponin is elevated, as they have
now become a high-risk patient.
(iii) Meanwhile, arrange an immediate stress test such as an
ECG exercise stress test (EST) if the repeat ECG and cardiac
biomarkers remain normal and the pain does not recur: