Acute Coronary Syndrome (ACS)
Emergency (acute) management:
1. ABC: Always ensure that the Airway, Breathing & Circulation are stabilised first.
2. 'MONA-BT'
Morphine
Oxygen
Nitrates
Aspirin
B-blockers
(Thrombolysis)
Details:
- Diamorphine: 2.5 – 5 mg (IV) PRN (not IM) & an anti-emetic (e.g. metoclopramide 10 mg IV)
- Oxygen: '100%' high-flow oxygen will save lives (do not be afraid to give Oxygen to patients with COPD - hypoxia will kill them fast, respiratory suppression takes time)
- GTN spray (sublingual): provides symptomatic relief
- Aspirin: 300 mg loading dose (chewed) (provided no contraindications (CIs), such as an active GI bleed). Alternatively use clopidogrel 300 mg (loading dose)
- ECG: perform an urgent 12-lead ECG
STEMIs (ST-Elevation Myocardial Infarctions)
Thrombolyse if:
1. Typical history of cardiac chest pain <12 hours in duration.
2. Any of:
a. ST elevation > 1 mm in 2 adjacent limb leads or > 2 mm in 2 contiguous chest leads
b. LBBB not known to be old
c. Posterior MI (ST elevation in V1 – V3) - this can be confirmed with other (posterior) lead
3. No CIs
Urgent CABG (Coronary Artery Bypass Graft)/PCI (Per-cutaneous Coronary Intervention) if:
1. ABP < 100 mmHg
2. Acute LVF
3. Continuing chest pain with <50% decrease in max ST-elevation @ 90mins after thrombolysis
NB:
- Aspirin has a better NNT than thrombolysis.
- PCI = percutaneous coronary intervention includes angioplasty and coronary vessel stenting.
NSTEMI - Non-ST Elevation Myocardial Infarction
Clotting:
- Anti-platelet drugs: aspirin (75 mg OD) or clopidogrel (75 mg OD)
- LMWH: stop if Trop –ve
- (consider Glycoprotein (GP) IIb/IIIa inhibitors if 'high-risk' ACS
Anti-ischaemia:
- Cardiac selective b-Blockers e.g. atenolol / metoprolol (aim for HR < 60)
- CIs for b-blockers include: asthma, ABP < 100 mm Hg, pulmonary oedema, heart block. Note that metoprolol is short-acting (and, with caution, can be used in cases of some of the usual CI, e.g. in asthmatics)
In diabetic patients:
- Consider a insulin-glucose infusion (if IDDM / NIDDM or BM > 11 mM) - this has beneficial effects on mortality as shown by the DIGAMI study (an IV sliding-scale followed by a subcutaneous insulin regimen improves survival @ 1 and 3years)
Other drugs to start once patient stabilised:
- ACE-Inhibitors e.g. ramipril (CI if ABP < 100 mmHg) save lives. HOPE study: ramipril decreased all-cause mortality in >55yr old patients with MI or risk factors for MI)
- Statin e.g. simvastatin 40 mg (stabilises plaque)
After discharge
- Smoking: help to stop
- Lifelong aspirin, ACE-I & statin
- Clopidogrel (6 months) in NSTEMI (also, for variable durations, if stents are in situ)
- Control other risk factors, e.g. hypertension, diabetes mellitus, etc.
Thrombolysis
Methods:
Aim for 'door-to-needle' time of < 20 mins.
Two options:
1. Streptokinase.
2. recombinant t-PA (tissue plasminogen activator): Use if previous streptopkinase treatment given, recent Strep. infection, < 4 hrs since symptoms onset, < 55 yrs old, anterior MI (better outcomes with tPa).
Contraindications:
- Bleeding (active GI bleeds or bleeding diathesis)
- Recent surgery / dental extraction (within last 2 weeks) or significant trauma (within last 2 weeks)
- CVS: aortic dissection suspected or hyptertension (BP > 200 / 110 mmHg)
- Neuro: CVA (cerebtrovascular accident, stroke) within last 6 months (or any other haemorrhagic incident) or head-injury within past 6 weeks
- Eyes: proliferative diabetic retinopathy or laser therapy for diabetes within past 1 week
- Pregnancy: currently pregnant or in post-partum period
Complications:
-'ABCDEF'
Anaphylaxis (more common with streptokinase)
Bleeding
CVA (more common with rt-PA)
Drop ABP (hypotension) esp. with streptokinase
thromboEmbolus
Fibrillation (reperfusion arrhythmias)
