Eddy Lang MDAttending StaffEmergency Department Jewish General Hospital

Update in reperfusion therapy for acute myocardial

infarction

Educational Process Objectives

• Use a problem-solving approach to address two controversial topics in MI reperfusion

• Review databases of research evidence

• Introduce the concept of the study synopsis

Clinical Scenario

• 52 year old male with chest pain x 2 hrs.

• No history of CAD, risk factors ++

• Severe central C/P with radiation and diaphoresis and SOB

• No known bleeding

• No head trauma

Clinical Scenario

• Pale, diaphoretic

• BP 140/70 Pulse 115 RR 24

• Chest: clear

• CVS: Normal HS; Ø JVD; Ø murmers

• Abdo: soft

• CNS: normal

Clinical Setting

• 4th year EM resident moonlighting at the Lakeshore

• Girlfriend/boyfriend working ED at JGH

• No formal transfer arrangement

• Arrange primary PTCA and transfer?

(ignore the politics)

Clinical Question

In patients with acute myocardial infarction who are candidates for reperfusion therapy but present to a center that doesn’t offer PCA does transport to a center with cath lab capabilities within a 3-hour window compared to early thrombolysis on-site reduce mortality?

Search Strategy

• Question type

• Resource: where would you look?

– systematic review

– shortcut reviews

– primary RCTs

– meta-search engines

– cutting edge studies

Systematic Review

Shortcut Review

10 trials 2 600 pts.

Shortcut Review

Shortcut Review

Shortcut Review

Primary Studies

Primary Studies

Meta-search engines

Cutting edge stuff

Cutting edge stuff

Cutting edge stuff

Clinical Scenario

• 52 year old male with chest pain x 2 hrs.

• No history of CAD, risk factors ++

• Severe central C/P with radiation and diaphoresis and SOB

• No known bleeding

• No head trauma

Clinical Setting

• 4th year resident moonlighting on a rural rotation

• Extremely well-stocked ED pharmacy

• Ø IIb/IIIa inhibitors

• PCI unavailable

• In addition to ASA what anti-thrombin therapy should you give?

• UFH (most familiar)? LMWH? Does it matter?

Clinical Question

In patients with acute myocardial infarction who are receiving thrombolytic therapy and ASA does adjuvant antithrombin therapy with LMWH in comparison with UFH reduce adverse cardiac events during the following 30 days without an unacceptable increase in bleeding?

Efficacy and safety of tenecteplase in combination with enoxaparin, abciximab, or

unfractionated heparin: the ASSENT-3 randomised trial in acute myocardial infarction

The ASSENT-3 InvestigatorsLancet 2001;358:605–13

ASSENT 3

Breakout tasks

• Develop a study synopsis

1. Maximum 5 sentences

• Appraise methodology

2. Prognosis before the start of the study

3. Prognosis after the start of the study

• Define the key issues in applicability

4. Why not use it

Aside from the experimental intervention, were groups treated equally?

Conclusions

• PCA:

• Even with 90 min additional delay PCA superior to lysis

• Evidence behooves the interventionist to come in at 2:00am

• Referral centers are coming

• Adjuvant anti-thrombotic therapy:

• Enoxaparin superior to UFH