c_nsteacs_mx
Mx of possible acute coronary syndrome without ST elevation (NSTEACS)
introduction
initial Mx in ED
triage 2 to a cardiac monitored cubicle
oxygen if SaO2 < 93% or if in shock (oxygen is no longer advised to be given routinely!)
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early 12 lead ECG
IV access & send bloods for FBE, U&E, glucose, cardiac enzymes (usually CK, troponin), (plus clotting profile if thrombolysis likely or patient is on
warfarin)
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CXR when available preferably whilst on cardiac monitor
serial ECG's and troponins (4hr and 6hr post most severe pain) whilst cardiac monitoring.
contact cardiology if either:
if low risk after serial troponins then:
consider alternative diagnoses
if very low risk for IHD then follow up by LMO
if pain is consistent with angina then commence daily aspirin, advise against exertion until further testing:
initial risk stratification
a subgroup of these patients can be regarded as sufficiently high risk even with normal initial ECG and troponin, that they warrant EARLY referral to cardiology with additional medical Mx and early coronary angiography rather than observation in an ED short stay observation unit and stress testing.
diagnosis and short term risk stratification should be based on a combination of clinical history, symptoms, ECG, biomarkers, and risk score results.
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the HEART score
perhaps the best tool for ED patients as of 2014 as it outperforms the TIMI and GRACE scores
1)
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parameter | score 0 | score 1 | score 2 |
*History | slightly suspicious | mod. suspicious | highly suspicious |
*ECG | normal | non-specific repolarisation disturbance | significant ST depression |
*Age | ≤ 45 years | 45 – 65 years | ≥ 65 years |
*Risk factors | no known factors | 1-2 risk factors | > 2 risk factors |
*Troponin | normal | 1-3x normal limit | ≥ 3x normal limit |
additional Mx according to risk stratification
coronary angiography with view to revascularisation appears to be appropriate for those patients with a risk of death or AMI at 1 yr of >10% and at 5 yrs of > 20%. Patients at lower risk do not appear to have benefit
2).
high risk group
eg. HEART score > 6
EARLY consultation with cardiology team as should be considered for early coronary angiography
medical therapy in addition to aspirin:
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grade B recommendation
300mg o load then 75mg daily
AVOID if:
likely to require early CABG surgery eg. severe widespread ST depression or haemodynamic instability
immediate coronary angiography anticipated (but should be given if > 6hrs delay for angiography)
risk of bleeding such as recent head injury or trauma, age > 75 years, etc.
clopidogrel should be ceased 5 days prior to CABG surgery
there is evidence for benefit of clopidogrel use for up to 12 months after ACS, and in those whom aspirin is C/I, especially if they have recurrent ischaemic events.
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additional antithrombotic Rx:
option 1:
option 2:
option 3:
in lab administration of iv GPIIb/IIIa inhibitors (particularly abciximab) may be preferable to short term upstream administration in high risk patients undergoing PCI. Pre-treatment with high-dose clopidogrel is not an adequate alternative to abciximab in patients undergoing PCI who have raised troponin levels.
4)
consider oral
beta adrenergic blockers (NOT iv unless severe HT or arrhythmia!!) in the 1st 24 hours (no hurry) unless C/I
(level I evidence, grade A recommendation)
contra-indications to beta blockers in acute coronary syndromes:
iv GTN for refractory pain (grade D recommendation)
ensure good glycaemic control for diabetics - consider insulin Rx whilst in hospital and for 3 or more months in selected patients (grade B recommendation)
statins Rx should be commenced for all patients with coronary heart disease (level II evidence, grade B recommendation)
ACE inhibitors should be commenced early after an ACS, and its use reviewed later (level II evidence, grade B recommendation)
usually warrant transfer to a coronary care unit (CCU) although cardiology team may elect to Mx some of these as for intermediate risk group (eg TIMI risk score < 3)
invasive Mx:
eg. HEART score 4-6
these patients can usually be transferred to an ED short stay observation unit or a chest pain unit for re-classification into either high risk or low risk group with:
if any features arise that place the patient in the high risk group, then Mx as for high risk group.
patients with normal serial troponins and no dynamic ECG changes can usually be Mx as for
low risk group, although should be referred for timely
cardiac stress testing - preferably
stress echo, or if this is C/I or not available, then a
stress MIBI
there are still dilemmas in the risk stratification and evaluation of this group of patients
5)
a normal ECG and troponin does not exclude ACS in higher risk patients
normal ECG, negative troponin, thus “low risk” - well not quite - you could still have a 10% risk of cardiac death or AMI in next 30days:
A Spanish study published in 2007 confirmed that non-specific ECG changes or raised troponin in the absence of ECG or CK evidence of infarct, do not add much to clinical risk of 30 day or long term risk of cardiac death or AMI if you clinically suspect their chest pain is due to IHD.
used a scoring tool giving:
30 day risk of cardiac death or AMI was (26 month risk in brackets):
1.7% (9%) if score < 3 and no ST depression on ECG and normal troponin
10.8% (26%) if score 3 or more and no ST depression on ECG and normal troponin
6.6% (30%) if ST depression on ECG but normal troponin
9.4% (25%) if no ST depression but troponin elevated
note these patients received aspirin and beta blockers and early stress testing. I'm guessing that their 30day risk would be even higher if they did not receive these interventions.
this is again highlighted with the HEART score - with normal ECG and normal troponin, you can still score 7 = 50% risk of cardiac event
low risk group
eg. HEART score < 4
“appropriate period of observation” with serial ECGs and troponins as for intermediate risk group if you feel the pain may be cardiac in nature.
depending on probability of ACS, either:
references and resources
c_nsteacs_mx.txt · Last modified: 2014/06/04 17:44 (external edit)