Paramedics play a critical role in STEMI management
Accumulating evidence supports reduction in delays to primary percutaneous coronary intervention (PCI) for patients with ST-elevation myocardial infarction (STEMI) through paramedic triage and early activation of the catheterisation laboratory.
In patients with STEMI and high risk features including extensive elevation or Killip class ≥ :
• Fibrinolysis followed by routine early coronary angiography; and
• PCI with intra-procedural glycoprotein (GP) IIb/IIIa inhibition
is associated with:
• Reductions in MI and ischaemia recurrence; and
• Reductions in death and recurrent MI; but
• Not mortality alone when compared with standard treatment.
Paramedics trained in reperfusion play a critical role in the timely management of STEMI. In a recent NZ study, the median time from initial emergency call to fibrinolysis treatment for paramedic-treated patients was 44 minutes vs. 133 minutes for those treated in hospital (P<0.0001). In-hospital and 30-day mortality was similar between groups; however, heart failure was less frequent in the pre-hospital therapy group.
The CAPTIM (Comparison of primary angioplasty and pre-hospital fibrinolysis in acute myocardial infarction) study followed 840 patients who had been managed in a pre-hospital setting within 6 hours of the onset of acute STEMI. In patients included in the study within 2 hours, 5-year mortality was significantly lower in the pre-hospital fibrinolysis group, 5.8%, than the primary angioplasty group 11.1% (p=0.04).
A 5 year follow up of 795 patients concluded that results were “consistent with the 30 day outcomes of the trial, showing similar mortality for primary PCI and a policy of pre-hospital lysis followed by transfer to an interventional centre”.
A recent addendum to the 2006 Guidelines for the Management of Acute Coronary Syndromes, states that “timely reperfusion remains a key treatment objective in the management of ST-elevation myocardial infarction (STEMI)”.
In remote and regional areas where there is the potential for long delays in transport to hospital, pre-hospital fibrinolysis is an attractive option. Widespread implementation requires an increase in training, resources, and equipment for ambulance services. Strong cooperation between cardiologists, emergency medicine doctors and paramedics is mandatory for optimal pre-hospital STEMI care.
2011 ACS Recommendations for Reperfusion in STEMI
1. Consider early routine angiography and revascularisation in patients receiving fibrinolysis regardless of the success of pharmacologic reperfusion (Grade A recommendation, Evidence Level I).
2. Antiplatelet therapies should be continued for 12 months for all stented patients (Grade A recommendation, Evidence Level II).
3. The use of mechanical thromboectomy techniques to reduce thrombus burden during primary PCI should be considered (Grade A recommendation, Evidence Level II).
The 2011 Addendum to the 2006 ACS Guidelines can be viewed in full at The National Heart Foundation of Australia website www.heartfoundation.org.au/