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First posted June 2007 by Charles Gomersall
Reperfusion
- Percutaneous coronary intervention (PCI) is the treatment of choice if
rapidly available
- Outcome is heavily dependent on time to reperfusion, particularly in
those patients presenting within 3 hours of onset of symptoms
- As a result the benefits of PCI must be balanced against the additional
administrative and transport time associated with PCI
- PCI is recommended for patients presenting 3-12 h of onset of symptoms
if:
- Door-balloon inflation time is reliably <90 mins
- Door-balloon time is reliably <60 mins more than door-needle (thrombolysis)
time
- Patient has severe heart failure or cardiogenic shock (outcome with
thrombolysis is poor)
- Patient has a contraindication to thrombolysis
- Patient has an anterior MI
- These recommendations are summarized in figure 1
Figure 2. Reperfusion algorithm for patients with STEMI presenting within 12
h of onset of pain
- May be some benefit from PCI in patients presenting >12 h from onset of
chest pain
- Recombinant tissue plasminogen activator is the thrombolytic of choice
although the absolute reduction in mortality compared with streptokinase is
low (~1%). Newer forms of t-PA (eg reteplase and tenecteplase) have the
advantage of bolus dosing (as opposed to infusion of alteplase) but are not
associated with reduced mortality.
Adjunctive therapy
- Aspirin
- 80-325 mg of non-enteric coated aspirin to chew and swallow as soon as
the diagnostic impression of ACS formed (patients presenting within 24 h).
Thereafter daily oral dose indefinitely
- β blockade unless contra-indicated
- Consider ACE inhibitor or angiotension
receptor blocker, particularly for patients with evidence of LV dysfunction
- Consider statin
- Administration of glycoprotein IIB/IIIa inhibitor, abciximab, before PCI
is associated with better flow in the infarct-related artery after PCI
- Thrombolysis with rt-PA should be followed by infusion of unfractionated
heparin, titrated to maintain APTT 1.5-2 times control
- The addition of clopidogrel 75 mg/day (with loading dose of 300 mg for
patients ≤75 years) to thrombolysis and aspirin is associated with better
outcome (click
here to
view paper)
Further reading
Ting HH et al. Narrative review: Reperfusion strategies for ST-segment elevation
myocardial infarction. Ann Intern Med, 2006; 145:610-7
Hahn SA,
Chandler C. Diagnosis and management of ST elevation myocardial infarction. A
review of the recent literature and practice guidelines. Mount Sinai J Med,
2006; 73(1):469-81
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