Pre-hospital thrombolysis is
associated with mortality reduction
and prognosis improvement in
patients with ST-elevation myocardial
infarction
Class n.7
Fmup_7@hotmail.com
Introduction
Acute Myocardial Infarction (AMI)
• Acute myocardial infarction
(AMI) is the most serious
manifestation of cardiovascular
diseases
• It is defined as the destruction
of myocardial tissue resulting
from insufficient supply of
oxygen to the heart muscle
2
1.http://www.emedicine.com/emerg/TOPIC327.HTM
LCA – left coronary artery;
RCA – right coronary artery;
1 – Occlusion;
2 – Myocardial infarction.
Atherosclerosis and trombi
formation
• The atherosclerosis is
responsible for the
majority of myocardial
infarction.
• There is formation of
thrombi in coronary
arteries
3
2. http://www.health-fitness.com.au/the-layers-of-the-heart-and-heart-attacks/
Diagnosis
• Symptoms and alert
• ECG alterations (ST-elevation)
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Symptoms and alert
• Identifying AMI signals (retrosternal discomfort or
dyspnea, for example) with subsequent activation of the
emergency number is the first step towards a speedy and
effective action leading to a reduction of injuries and
consequent harm to the patient.
http://www.youtube.com/watch
?v=22bDs8teiZA&feature=relate
d
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ECG
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• An electrocardiogram is a
noninvasive transthoracic
graphic produced by an
electrocardiograph, which
records the electrical activity
of the heart over time.
• The typical ST segment
duration is usually around
0.08 sec (80 ms). An
elevation of >1mm and
longer than 80 milliseconds
may indicate myocardial
infarction.
ECG showing ST-segment elevation (orange)
and reciprocal changes (blue) in the inferior
leads.
3.http://www.ecglibrary.com/
Treatment
• In acute myocardial infarction with ST-segment
elevation the best treatment is reperfusion in the first
2 hours after the onset of symptoms.
Reperfusion
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Pharmacological
Mechanical
Thrombolytic Therapy
Angioplasty
4. ACC/AHA Guidelines for the
management of patients with STelevation myocardial infarction.
5. JAMA, 287(15): 1943–1951.
Study Aims and Question
PHT
Develop a study that could lead us to an answer to the question:
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Is PHT beneficial in terms of
morbidity and mortality on patients
with ST-elevation myocardial
infarction?
Objectives
• Determine if pre-hospital thrombolysis is associated
with reduction in early and late (1 year) cardiovascular
mortality in patients with ST elevation myocardial
infarction.
• Evaluate if pre-hospital trombolysis is associated with
prognosis improvement such as: hospital stay, left
ventricular ejection fraction, reenfartion rates,
reenfartion readmission rates.
• Determine if pre-hospital thrombolysis performed by
non medical teams is associated with and increase in
complication rates.
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Methods
• Search at Medline, ISI Web of Knowledge and Scopus
using a predefined Query and select the ones that are
related to our objective (the chosen articles are according
the inclusion and exclusion criteria).
In order to advance for
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Systematic review of prospective
cohort studies and posterior
metanalysis.
Query
(Thrombolysis OR Fibrinolytic Agents OR Thrombolytic Therapy)
AND ("Acute Myocardial Infarction" OR Myocardial Infarction OR
"ST-Elevation Myocardial Infarction") AND ("Pre-hospital" OR "Early"
OR “Prehospital”) AND (“Treatment Delay OR “Delay” OR 1-year
Outcome OR One Year Outcome)
• Database: Medline, ISI Web of Knowledge and
Scopus
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Inclusion and exclusion criteria
Inclusion:
Exclusion:
- Follow-ups till 1 year;
-Study language: Non-english studies;
- Study type: Clinical trials and Cohort
studies only;
-Thrombolytic type: 1st generation
thrombolytics;
-With ST-elevation;
- Comparison between AMI and
trombolytic treatment inexistent;
- PHT treatment with trombolytics;
- Comparison between pre-hospital and inhospital treatment.
- Studies that compare PHT with factors
beyond our interest;
- Studies with no abstract.
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Flowchart
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Article Selection
ISI Web ok Knowledge
Medline
Scoppus
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464 read
962 read
417 read
11 selected
2 selected
9 selected
Example
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Prehospital thrombolysis in a rural community: short- and long-term
survival.
McAleer B, Ruane B, Burke E, Cathcart M, Costello A, Dalton G, Williams JR,
Varma MP.
Cardiac Unit, Erne Hospital, Enniskillen, Northern Ireland.
In order to assess the feasibility and outcome of using prehospital thrombolysis
in acute myocardial infarction in a rural community, we performed an open
randomized study of patients with symptoms of acute myocardial infarction of
less than 6 hours. One hundred and forty-five patients with acute myocardial
infarction were allocated to receive IV streptokinase prehospital by means of a
mobile coronary care unit (MCCU) (n = 43) or to receive IV streptokinase in
hospital (n = 102). The mean delay time to treatment was 138 minutes (MCCU
group) and 172 minutes (hospital group) (p less than 0.02). Reperfusion time was
88 minutes for the MCCU group and 92 minutes for the hospital group. Mortality
at 14 days was 2.3% for the MCCU group and 11.7% for the hospital group (p less
than 0.05). Six month mortality was 4.9% for the MCCU group and 17.3% for the
hospital group (p = 0.03). Mortality at 1 year was 6.1% for the MCCU group and
20.0% for the hospital group (p = 0.04). There were no significant adverse events
in either treatment group. Thus, prehospital thrombolysis by streptokinase is
feasible and allows significant reduction in the delay time to treatment initiation.
There are encouraging improvements in both short- and long-term survival with
no apparent reduction in safety profile.
PMID: 1520646 [PubMed - indexed for MEDLINE]
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Calendar
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References
1.
2.
3.
4.
5.
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Drew Evan Fenton et al. Myocardial Infarction [Internet]. New York: eMedicine
Clinical Knowledge Base; [updated Oct 10, 2008]. Available from:
http://www.emedicine.com/emerg/TOPIC327.HTM
Dean Jenkins, Stephen Gerred. ECG Library [internet] [updated Oct 12, 2002].
Available from: http://www.health-fitness.com.au/the-layers-of-the-heart-andheart-attacks/
Dean Jenkins, Stephen Gerred. ECG Library [internet] [updated Oct 12, 2002].
Available from http://www.ecglibrary.com
American College of Cardiology (ACC) and American Heart Association (AHA)
(2004). ACC/AHA Guidelines for the management of patients with ST-elevation
myocardial infarction. Report of the ACC/AHA Task Force on Practice Guidelines.
Aversano T, et al. Thrombolytic therapy vs. primary percutaneous coronary
intervention for myocardial infarction in patients presenting to hospitals without
on-site cardiac surgery. JAMA 2002 April 7; 287(15): 1943–1951.
References
6. Erik Björklund, Ulf Stenestrand, Johan Lindbäck, et al. Pre-hospital thrombolysis
delivered by paramedics is associated with reduced time delay and mortality in
ambulance-transported real-life patients with ST-elevation myocardial infarction.
European Heart Journal 2006 May; 27(10):1146-52.
7. Danchin N, Blanchard D, Steg PG, et al. Impact of pre-hospital thrombolysis for acute
myocardial infarction on 1-year outcome: results from the French Nationwide USIC
2000 Registry. Circulation 2004 Oct 5;110(14):1909-15.
8. Danchin N, Durand E, Blanchard D. Pre-hospital thrombolysis in perspective.
Overview of current guidelines and data from trials and registries on the best
perfusion approach for acute MI with ST-elevation. European Heart Journal 2008
Oct 23. [Epub ahead of print]
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References
9. S Goodacre, A-M Kelly, D Kerr. Potential impact of interventions to reduce times
to thrombolysis. Emergency Medicine Journal 2004 Sep;21(5):625-9.
10. J Wilkinson, K Foo, N Sekhri, J Cooper, et al. Interaction between arrival time
and thrombolytic treatment in determining early outcome of acute myocardial
infarction. Heart 2002 Dec;88(6):583-6.
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