Transcript Document

Acute Coronary
Syndrome
Muhammad Asim Rana MRCP(UK)
Worldwide Statistics
Each year:
 > 4 million patients are admitted with
unstable angina and acute MI
 > 900,000 patients undergo PTCA with or
without stent
Myocardial Ischemia

Spectrum of presentation
silent ischemia
 exertion-induced angina
 unstable angina
 acute myocardial infarction
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STEMI
NSTEMI
Cumulative 6-month mortality
from ischemic heart disease
Deaths / 100 pts / month
25
N = 21,761; 1985-1992
Diagnosis on adm to hosp
20
15
Acute MI
Unstable angina
Stable angina
10
5
0
0
1
2
3
4
5
Months after hospital admission
Duke Cardiovascular Database
6
Percentage of deaths from
heart disease
others
23%
ACS
48%
Hypertension
5%
CHF
5%
Atherosclerosis
2%
0.5%
0.5%
Stroke
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Myocardial infarction remains a major cause
of death despite contemporary therapeutic
strategies.
Diagnosis in the intensive care unit is
challenging, but is essential to target
therapy accurately.
In patients admitted to the intensive care
unit, myocardial infarction is observed to
occur frequently, often without being
clinically apparent, with a high associated
mortality.
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Myocardial infarction (MI) in the critically
ill presents a diagnostic challenge to the
physician and is associated with a
particularly adverse outcome for the patient.
Such patients have high metabolic demands
and are often subject to sustained adverse
physiology.
Typical signs and symptoms can be difficult
to elicit and surrogate physiological markers
of impaired coronary perfusion masked or
misinterpreted in the context of the index
pathology.
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Cardiac troponin measurements and the 12lead echocardiogram (ECG) remain
sensitive in this setting, but specificity
decreases, resulting in diagnostic
uncertainty.
Recent consensus guidelines from the
European Society of Cardiology, American
College of Cardiology Foundation, American
Heart Association and World Heart
Federation emphasise the role of cardiac
biomarkers in defining MI.
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Diagnosis requires a rise and/or fall in
serum levels (preferably troponin) together
with evidence of myocardial ischaemia
defined: clinically by patient history;
electrocardiographically (new ST-T wave
changes, new left bundle branch block or
evolving pathological Q waves); or by
imaging evidence of new regional wall
motion abnormality.
Acute Coronary Syndrome
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Definition
The term ACS refers to a spectrum of
presentations caused by myocardial
ischemia that includes
Unstable Angina
Non ST elevation myocardial infarction
ST elevation myocardial infarction
Ischemic Heart Disease
Evaluation
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Based on the patient’s
History / Physical exam
 Electrocardiogram
 Biochemical markers
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Patients are categorized into 3 groups
Non-cardiac chest pain
 Unstable angina
 Myocardial infarction (STEMI,NSTEMI)

Acute Coronary Syndrome
The embracing term reflects the
common pathophysiology of
plaque disruption
Intravascular thrombosis
and
Impaired myocardial blood supply
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STEMI is the result of complete epicardial
occlusion following plaque disruption &
leads to propagation of thrombus &
epicardial vasoconstriction
NSTEMI is incomplete & transient
epicardial occlusion with platelet-rich &
phasic distal embolisation
Pathophysiology
Pathophysiology (cont’d)
Pathophysiology (cont’d)
Formation of haemostatic plaque
Patients withClinical
an ACS mayFeatures
complain of a new
onset of
Exertional chest pain
Chest pain at rest
or
A deterioration of pre-existing angina.
However, some patients present with atypical
features
including
Indigestion
Pleuritic chest pain
or
Dyspnoea
Diagnosis
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ECG
Biochemical Markers
The Cardiac Troponin Complex
Myoglobin
Creatinine-Kinase MB
ECG
Biochemical markers
Unstable Angina
Anti-platelet Therapy
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Abciximab (Abciximab is a monoclonal antibody
that binds tightly to GP (glycoprotein) IIb/IIIa
receptors and has a long half-life)
EPIC Trial
effective in preventing death, MI, and abrupt
closure associated with coronary angioplasty
Unstable Angina
Anti-platelet Therapy
Abciximab
CAPTURE
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At 30 days, there was a 29% reduction in the
primary composite endpoint of death, MI, or
urgent revascularization in the abciximab
group
Lancet 1997;349:1429-1435
Unstable Angina
Anti-platelet Therapy
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Tirofiban (Tirofiban is a small non-peptide that
rapidly blocks the GPIIb/IIIa receptors and is
reversible in 4–6 hours)
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PRISM (Platelet Receptor Inhibition for Ischemic
Syndrome Management)
3,200 patients with unstable angina were treated with
either heparin or tirofiban
At 48 hours, there was significant risk reduction (5.9%
to 3.6%) in the rate of death, MI, or refractory
ischemia.
N Engl J Med 1998;338:1498-505
Unstable Angina
Anti-platelet Therapy
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Tirofiban
PRISM -PLUS (Platelet Receptor Inhibition
for Ischemic Syndrome Management in
Patients Limited by Unstable Signs and
Symptoms)
 randomized 1,915 patients with UA and non-QMI to tirofiban alone, heparin alone, or a
combination of the two (all received aspirin)
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N Engl J Med 1998;338:1488-97
Unstable Angina
Anti-platelet Therapy
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Eptifibatide (Eptifibatide is a cyclic peptide that
selectively inhibits GPIIb/IIIa receptors, but has
a short half-life and wears off in 2–4 hours.)
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PURSUIT (Platelet IIb/IIIa Underpinning the
Receptor for Suppression of Unstable Ischemia Trial)
~11,000 patients admitted with unstable angina or nonQ-wave myocardial infarction
a broad-based trial encompassing a variety of clinical
practices and practice styles
NEJM 1998;339:436-443
10/98
MedSlides.com
36
Unstable Angina
Anti-platelet Therapy
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Eptifibatide
PURSUIT
 randomized to eptifibatide or placebo; all
patients received aspirin and heparin
 significantly reduced the risk of death and MI
at 30 days from 15.7% to 14.2%, a 9% risk
reduction
NEJM 1998;339:436-443
10/98
MedSlides.com
37
Unstable Angina
Anti-platelet Therapy
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Summary
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the four “P trials” (PRISM, PRISM-PLUS,
PARAGON, PURSUIT)
all show reduction of death rate between
1.3% and 3.4% - in addition to the benefit of
aspirin
useful in the management of patients with
unstable angina and MI without ST elevation
Unstable Angina
Anti-coagulant Therapy
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Heparin
recommendation is based on documented
efficacy in many trials of moderate size
 meta-analyses of six trials showed a 33%
risk reduction in MI and death, but with a two
fold increase in major bleeding
 Titrate PTT to 2x the upper limits of normal

1. Circulation 1994;89:81-88
2. JAMA 1996;276:811-815
Unstable Angina
Anti-coagulant Therapy
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Low-molecular-weight heparin
advantages over heparin:
better bio-availability
 higher ratio (3:1) of anti-Xa to anti-IIa activity
 longer anti-Xa activity, avoid rebound
 induces less platelet activation
 ease of use (subcutaneous - qd or bid)
 no need for monitoring
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ESSENCE Trial
incidence of death, MI, or recurrent angina
25
Day 14
Day 30
25
20
20
15
23.3%
19.8%
19.8%
16.6%
P=0.016
15
P=0.019
10
10
5
5
n=1564 n=1607
n=1564 n=1607
0
0
heparin Lovenox
heparin Lovenox
N Eng J Med 1997;337:447-452
ACS
Clinical Diagnosis
MONA:
Morphine + antiemetic
Oxygen
Nitrates
Aspirin 300 mg stat
About 33% of patients
with ACS and normal
CK (and no ECG
changes of infarction)
have elevated cTn.
Such patients with
elevated cTn are,
however, four times
more likely to suffer
further infarction or
death in the next 30
days.
Blood Tests:
Troponin at 12 hours after onset
of pain, U&E, cholesterol, FBC,
coagulation
Admission or subsequent ECG
Relationship between cardiac troponin I levels and risk of
death in patients with the acute coronary syndrome (ACS).
High Risk ECG changes:
(2 or more contiguous leads)
ST depression > 1mm
T inversion > 1mm
Transient BBB
Minor/ transient ST elevation
High Risk Clinical features:
Ongoing rest pain.
Haemodynamic instability.
Arrythmias
NO
Troponin Elevated?
Inconclusive
NO
ZO
Consider further
investigations:
Perfusion scan
Angiography
Cardiology Referral
Able to exercise ?
YES
Exercise Tolerance
Test
Normal
Low Risk
(Discharge)
Positive
High
Risk
TIMI Score
One point is scored for
each variable
0- 2 : Low risk
3- 4 : Intermediate risk
5-7 : High risk
High Risk ECG changes:
(2 or more contiguous leads)
ST depression > 1mm
T inversion > 1mm
Transient BBB
Minor/ transient ST elevation
High Risk Unstable
Ongoing pain
Dynamic high risk
ECG changes
GPIIbIIIa inhibitors.
Consider urgent
cardiac cath.
Consider pre-morbid
state and suitability
for revascularisation.
High Risk Clinical features:
Ongoing rest pain.
Haemodynamic instability.
Arrythmias
Troponin Elevated
High Risk
1.
2.
3.
4.
LMWH
Clopidogrel 300 mg stat, 75mg OD
Aspirin 75 mg OD
Beta Blockers: metoprolol 25 mg
tds
5. Hyperglycaemic control DIGAMI
protocol, if RBS > 10 mmol
6. Morphine and / or IV nitrates if
continuing pain, titrate to pain and
blood pressure.
High Risk Stable
Cardiac Cath.
consider premorbid state and
suitability for
revascularisation
Acute STEMI
ECG criteria
1 mm ST elevation
in at least 2 limb
leads
2 mm ST elevation
in at least 2
precordial leads
LBBB with typical
clinical presentation
Immediate
Triage
12 Lead ECG
Showing thrombolyseable
criteria
Definite STEMI
Extra ECG
requirements
Inferior ST
elevation Do Rt.
ECG
Posterior changes
Posterior ECG
Primary PCI
Thrombolysis
(if PCI unavailable immediately)
Target < 20 min
Door-needle time in > 75%
patients
MONA:
Morphine + antiemetic
Oxygen
Nitrates
Aspirin 300 mg stat
Ix on admission
U&E, FBC, Cholest,
coagulation
Repeat
12 hrs Troponin, ECG
Control RBS
Tenectoplase (TKN-tPA)
Drug of choice with LMWH
for pts <75 yrs independent
of site of infarct
Streptokinase (SK)
Consider for pts > 75 yrs due
to lower incidence of ICH
Repaeat ECG 90 min from comencement of lytic Aim: > 50%
reduction in peak ST segment elevation
REASSESS
Risk assessment & secondary prevention
Aspirin
Statin
Early beta blokade
Ace- inhibitors
ETT or angiogram pre discharge
Rehablitation
Consider patient’s pre morbid state & suitability for
revascularisation
Failed Reperfusion
Haemodynamics compromise
Continuing pain
Disscuss suitability for rescue PCI
There is no evidence of benefit from
readministration of thrombolysis
Contraindications to thrombolysis
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ABSOLUTE
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RELATIVE
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Active GI Bleed
Aortic Dissection
Previous ICH
Stroke<2 months
Intracranial aneurysm/
neoplasm
Head injury<2 months
Pericarditis
Pancreatitis
Warfarin/INR>3
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Traumatic CPR
Surgery<10 days
Arterial Puncture<24 hrs
SBP>180
Bleeding Tendency
Trauma
Pregnancy
Bacterial Endocarditis
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Contraindications vary slightly between thrombolytics
Thrombolysis not suitable
Thrombolysis Contraindicated or
Cardiogenic shock
Patient presented >12 hrs
LMWH
Nitrates & Morphine
Admit in ICCU
Risk assessment & secondary prevention
Aspirin
Statin
Early beta blokade
Ace- inhibitors
ETT or angiogram pre discharge
Rehablitation
Thank you very much