Transcript ACC/AHA Guidelines for the Management of Patients with ST Elevation Myocardial Infarction;Ahmad Aslam, M.D. Prasantha Bathini, M.D. Robert Smith, M.D. Cardiac Cath Conference July 13, 2004

ACC/AHA Guidelines for the
Management of Patients with ST
Elevation Myocardial Infarction;
2004
Ahmad Aslam, M.D.
Prasantha Bathini, M.D.
Robert Smith, M.D.
Cardiac Cath Conference
July 13, 2004
Participants in Updated Guidelines
Evidence Based Medicine;
What’s the Problem?
“There is an unsettling truth about the practice
of medicine. …study after study shows that few
physicians systematically apply to everyday
treatment the scientific evidence about what
works best.”
Millenson, ML. Demanding Medical Excellence: Doctors
and Accountability in the Information Age. 1997
How Should We Be Dealing With This?
ACC/AHA Practice Guidelines:
Classification of Benefit
Class I
Conditions for which there is evidence and/or general agreement that a
given procedure or treatment is useful and effective
Class IIa
Conditions for which there is conflicting evidence and/or divergence of
opinion about the usefulness/efficacy of a procedure or treatment.
However, the treatment/procedure is reasonable and is probably useful
and effective
Class IIb
Conditions for which there is conflicting evidence and/or divergence of
opinion about the usefulness/efficacy of a procedure or treatment.
However, the treatment/procedure may be reasonable. The usefulness
and effectiveness is not well established
Class III
Conditions for which there is evidence and/or general agreement that
the procedure/treatment is not useful or effective and in some cases
may be harmful
ACC/AHA Practice Guidelines:
Level of Evidence
A (highest)
The data were derived from multiple randomized clinical
trials that involved large numbers of patients
B (intermediate)
The data were derived from a limited number of
randomized trials that involved small numbers of patients,
or from careful analysis of non-randomized studies or
observational registries
C (low)
A lower rank was given when expert consensus was the
primary basis for the recommendation
Epidemiology
• In the U.S., there were 1,680,000 discharges
for ACS in the year 2001
• Approximately 500,000 of these were
STEMI’s
Prehospital Issues
Class I
Patients with symptoms of STEMI should be transported to
the hospital by ambulance rather than by friends or
relatives. (Level of Evidence: B)
Healthcare providers should instruct patients in whom
NTG has been prescribed to take ONE NTG dose
sublingually in response to chest pain. If the pain is
worsened or unimproved after 5 minutes, the patient
should be instructed to call 911 (Level of Evidence: C)
Initial Recognition and
Management in the ED
“Hospitals should establish multidisciplinary teams
(including primary care physicians, emergency
medicine physicians, cardiologists, nurses, and
laboratorians) to develop guideline-based,
institution-specific written protocols for triaging
and managing patients who are seen in the
prehospital setting or present to the ED with
symptoms suggestive of STEMI.”
Class I, Level of Evidence: B
Targeted History
• Ascertain whether the patient has had prior episodes of
myocardial ischemia (stable or unstable angina, MI,
CABG, or PCI)
• Focus on chest discomfort and associated symptoms
• HTN?
• DM?
• Assess for possibility of aortic dissection
• Assess risk of bleeding
• Assess for clinical cerebrovascular disease (amaurosis
fugax, face/limb weakness or clumsiness, sensory loss,
ataxia, vertigo
Class I, Level of Evidence: C
Physical Exam
Class I
To aid in the diagnosis and assessment of the
extent, localization, and presence of complications
of STEMI. (Level of Evidence: C)
A brief, focused neurologic exam in order to look
for evidence of prior stroke or cognitive defects
(before administering fibrinolytics) . (Level of
Evidence: C)
ECG
Class I
Should be done within 10 minutes of arrival. (Level of
Evidence: C)
If the initial ECG is not diagnostic of STEMI but the
clinical suspicion is high, serial ECG’s (5-10 minute
intervals) or continuous 12 lead ST segment monitoring
should be performed. (Level of Evidence: C)
With inferior STEMI, right sided ECG should be
performed in order to look for ST elevation suggestive of
RV infarct. (Level of Evidence: B)
Inferior Infarct
V1
V2
V3
V4
V5
V6
Right Sided Leads
V3(R)
V4(R)
V5(R)
V6(R)
V2 (R)
V1 (R)
Inferior/RV Infarct
(R)
(R)
(R)
(R)
(R)
(R)
Laboratory Examinations
Class I
Cardiac-specific troponins should be used as the optimum
biomarkers for the evaluation of patients with STEMI who
have coexistent skeletal muscle injury. (Level of
Evidence: C)
For patients with STEMI on the ECG and symptoms,
reperfusion therapy should be initiated immediately and is
not contingent on a biomarker assay. (Level of Evidence:
C)
ECG
The 12 lead ECG is the center of the
therapeutic decision pathway because of the
strong evidence that ST segment elevation
identifies patients who benefit from
reperfusion therapy
Imaging
Class I
Patients with STEMI should have a portable CXR, but this
should not delay implementation of reperfusion therapy
unless a contraindication, such as aortic dissection, is
suspected. (Level of Evidence: C)
High quality pCXR, TTE and or TEE, and contrast chest
CT or MRI should be used to differentiate STEMI from
dissection in patients for whom this distinction is unclear.
(Level of Evidence: B)
Initial Management; Oxygen
Class I
Supplemental O2 should be administered to
patients with arterial oxygen desaturation (SaO2
less than 90%). (Level of Evidence: B)
Class IIa
It is reasonable to administer O2 to all patients
with uncomplicated STEMI during the first 6
hours. (Level of Evidence: C)
Initial Management: Nitrates
Class I
Patients with ongoing ischemic discomfort should receive
SL NTG (0.4mg) every 5 minutes for a total of 3 doses,
after which an assessment should be made about the need
for IV NTG. (Level of Evidence: C)
IV NTG is indicated for relief of ongoing ischemic
discomfort, control of HTN, or management of pulmonary
congestion. (Level of Evidence: C)
Initial Management: Nitrates
Class III
Nitrates in all forms should be avoided in patients
with an initial systolic blood pressure less than
90mmHg or greater than or equal to 30mmHg
below baseline, in patients with marked
bradycardia or tachycardia, and in patients with
known or suspected RV infarction. In view of
their marginal treatment benefits, nitrates should
not be used if hypotension limits the
administration of Beta Blockers
Initial Management: Analgesia
Class I
MSO4 (2-4mg IV with increments of 2-8mg IV
repeated at 5-15 minute intervals) is the analgesic
of choice for management of pain associated with
STEMI. (Level of Evidence: C)
Initial Management: Aspirin
Class I
Aspirin should be chewed by patients who have
not taken aspirin before presentation with STEMI.
The initial dose should be 162mg (Level of
Evidence: A) to 325 mg. (Level of Evidence: C)
Although some trials have used enteric-coated
ASA for initial dosing, more rapid buccal
absorption occurs with non-enteric coated
formulations
Initial Management: Beta-Blockers
Class I
Oral BB therapy should be administered promptly to those
patients without a contraindication, irrespective of
concomitant fibrinolytic therapy or performance of
primary PCI. (Level of Evidence: A)
Class IIa
It is reasonable to administer IV BB promptly to STEMI
patients without contraindications, especially if a
tachyarrhythmia or HTN is present. (Level of Evidence: B)
Reperfusion
Class I
All STEMI patients should undergo rapid
evaluation for reperfusion and have a
reperfusion strategy implemented promptly
after contact with the medical system.
(Level of Evidence: A)
Reperfusion
• For fibrinolytic therapy, goal is door to needle
time of 30 minutes
• For PCI, goal is door to balloon inflation time of
90 minutes
• These goals may not be relevant for patients with
an appropriate reason for delay such as uncertainty
about the diagnosis, life threatening conditions
(e.g., respiratory failure), or delays associated with
patient’s informed failure to consent
Reperfusion
• These goals should not be understood as “ideal”
times, but the rather the longest times that should
be considered acceptable
• Systems that are able to achieve more rapid times
should be encouraged
Selection of Reperfusion Strategy
• Several issues should be considered in
selecting the type of reperfusion therapy
–
–
–
–
Time From Onset of Symptoms
Risk from STEMI
Risk of Bleeding
Time Required for Transport to a Skilled PCI
laboratory
Time From Onset of Symptoms
• Time from onset of symptoms to fibrinolytic
therapy is an important predictor of MI size and
patient outcome1
• The efficacy of fibrinolytic agents for lysing
thrombus diminishes with time2
• Fibrinolytic therapy administered within the first 2
hours (especially the first hour) can occasionally
abort MI and dramatically reduce mortality3,4
1Boersma,
E., et al. Lancet, 1996;348:771-775
2Zeymer et al. Am Heart J, 1999:137:34-38
3FTT Collaborative Group. Lancet, 1994;343:311-322
4Weaver, WD et al. JAMA, 1993;270:1211-1216
Time From Onset of Symptoms
• Conversely, the ability to produce a patent infarct artery is
much less dependent on symptom duration in patients
undergoing PCI
• Several reports claim no influence of time delay on
mortality rates when PCI is performed after 2-3 hours of
symptom duration1,2
• However, after adjustment for baseline characteristics, time
from symptom onset to balloon inflation is significantly
correlated with 1 year mortality in patients undergoing
primary PCI for STEMI3
1FTT
Collaborative Group. Lancet, 1994;343:311-322
2Brodie
et al. Am J Cardiol, 2001;88:1085-1090
3Williams, D. Circ, 2004;109:1806-1808
Risk From STEMI
• In patients at high risk for adverse outcome from
STEMI, such as those with cardiogenic shock or
high TIMI risk score1, compelling evidence exists
that favors a PCI strategy
1Morrow
et al. Circ. 2000;102:2031-2037
Risk of Bleeding
• If both types of reperfusion therapy are
available, PCI is favored in patients at high
risk for bleeding
• If PCI is not available, the risks and benefits
of fibrinolysis must be weighed
Transport Time to PCI Lab
• For facilities that can offer PCI, the literature suggests that
this approach is superior to fibrinolysis1
• The trials comparing fibrinolysis to PCI, however, were
conducted prior to the advent of more recent PCI and
pharmacologic therapies
• When a composite end point of death, nonfatal recurrent
MI, or stroke is analyzed, much of the superiority of PCI is
driven by the reduction of nonfatal recurrent MI2
1Magid
et al. JAMA. 2000;284:3131-3138
2Boersma, E., et al. Lancet, 1996;348:771-775
PCI vs. Fibrinolysis; 4-6 Weeks
PCI vs. Fibrinolysis; Long Term
Reperfusion Strategy (cont.)
• As the time delay for performing PCI increases,
the mortality benefit of PCI over fibrinolysis
decreases1
• Compared with a fibrin-specific lytic agent, a PCI
strategy may not reduce mortality when a delay
greater than 60 minutes is anticipated vs.
immediate lytic therapy
1Nallamothu
et al. Am J. Cardiol. 2003;92:824-826
Reperfusion Strategy (cont.)
• Given the current literature, it is not possible to
say definitively that a particular reperfusion
approach is superior for all patients in all clinical
settings at all times of day
• The main point is that some type of reperfusion
therapy should be selected for all appropriate
patients with suspected STEMI
• The appropriate and timely use of some
reperfusion therapy is likely more important than
the choice of therapy
Step I: Assess time and risk
- Time since onset of symptoms
- Risk from STEMI
- Risk of fibrinolysis
- Time required for transport to a skilled PCI lab
Step II: Determine whether fibrinolysis or invasive strategy is preferred
Fibrinolysis is generally preferred if
- Early presentation (3 hours or less
and delay to invasive strategy)
- Invasive strategy is not an option
- Cath lab not available
- Vascular access difficulties
- Lack of access to a skilled lab
- Delay to invasive strategy
Invasive strategy is generally preferred if
- Skilled PCI lab available with
surgical backup
- High risk from STEMI
- Cardiogenic shock
- Killip class > or = to 3
- Contraindications to fibrinolysis
including increased risk of bleeding
and ICH
- Late presentation
- Symptom onset more than 3 hours
- Diagnosis of STEMI is in doubt
Fibrinolytic Therapy
Class I
STEMI patients presenting to a facility without the capacity for expert,
prompt intervention (primary PCI with 90 minutes of first medical
contact) should undergo fibrinolytic therapy. (Level of Evidence: A)
In the absence of contraindications, fibrinolytic therapy should be
administered to STEMI patients with symptom onset within the prior
12 hours and ST elevation greater than 0.1mV in at least 2 contiguous
precordial leads or at least 2 adjacent limb leads. (Level of Evidence:
A)
In the absence of contraindications, fibrinolytic therapy should be
administered to patients with symptom onset within the prior 12 hours
and new or presumably new LBBB. (Level of Evidence: A)
Fibrinolytic Therapy
Class IIa
In the absence of contraindications, it is reasonable to administer
fibrinolytic therapy to STEMI patients with symptom onset within the
prior 12 hours and ECG findings consistent with true posterior MI.
(Level of Evidence: C)
In the absence of contraindications, it is reasonable to administer
fibrinolytic therapy to patients with symptoms of STEMI beginning
within the prior 12-24 hours who have continuing ischemic symptoms
and ST elevation greater than 0.1mV in at least 2 contiguous precordial
leads or at least 2 adjacent limb leads. (Level of Evidence: B)
True Posterior MI
V1
V2
V3
V4
V5
V6
True Posterior MI
V1
V2
V3
V4
V5
V6
V7
V9
V8
True Posterior MI
Fibrinolytic Therapy
Class III
Fibrinolytic therapy should not be administered to
asymptomatic patients whose initial symptoms of
STEMI began more than 24 hours earlier. (Level
of Evidence: C)
Fibrinolytic therapy should not be administered to
patients whose ECG shows only ST segment
depression unless true posterior MI is suspected.
(Level of Evidence: A)
Contraindications and Cautions for Fibrinolysis use in STEMI
Relative Contraindications
Absolute Contraindications
- Any prior ICH
- Known structural cerebral
vascular lesion (e.g., AVM)
- Known malignant intracranial
neoplasm (1o or 2o)
- Ischemic stroke within 3 months
except acute ischemic stroke
within 3 hours
- Suspected aortic dissection
- Active bleeding or bleeding diathesis
(except menses)
- Significant closed head or facial
trauma within 3 months
- History of chronic, severe,
poorly controlled HTN
- Severe, uncontrolled HTN on
presentation (SBP>180, DBP>110)
- Hx of prior ischemic stroke >3 months,
dementia, or known IC pathology not
listed in contraindications
- Traumatic or prolonged CPR (>10 min)
or major surgery (<3 weeks)
- Recent internal bleeding (2-4 weeks)
- Noncompressible vascular punctures
- For Streptokinase/Anistreplase: prior
exposure (>5 days) or prior allergic rxn
- Pregnancy
- Active peptic ulcer
- Current use of anticoagulants;
the higher the INR, the higher
the risk
Percutaneous Coronary Intervention
Class I
If immediately available, primary PCI should be performed
in patients with STEMI (including posterior MI), or in
patients with new LBBB who can undergo PCI of the
infarct artery within 12 hours of onset of symptoms. (Level
of evidence: A)
PCI must be performed in a timely fashion (door 
balloon time 90 minutes) by persons skilled in the
procedure (greater than 75/year). (Level of evidence: A)
Percutaneous Coronary Intervention
Class I
Primary PCI should be performed for patients younger
than 75 years with STEMI or LBBB who develop shock
within 36 hours of MI and are suitable for
revascularization that can be performed within 18 hours of
shock. (Level of Evidence: A)
Primary PCI should be performed in patients with severe
CHF and/or pulmonary edema (Killip class III) and onset
of symptoms within 12 hours. Door  balloon should be
within 90 minutes. (Level of Evidence: B)
Percutaneous Coronary Intervention
Class IIa
Primary PCI is reasonable for patients >75 yrs who
develop shock within 36 hours of MI and are suitable for
revascularization that can be performed within 18 hours of
shock. (Level of Evidence: B)
It is reasonable to perform primary PCI for patients with
onset of symptoms in prior 12-24 hours and severe CHF
(Level of Evidence: C), hemodynamic or electrical
instability (Level of Evidence: C), or persistent ischemic
symptoms (Level of Evidence: C)
Percutaneous Coronary Intervention
Class III
PCI should not be performed in a non-infarct
artery at the time of PCI in patients without
hemodynamic compromise. (Level of Evidence:
C)
Primary PCI should not be performed in
asymptomatic patients more than 12 hours after
onset of STEMI if they are hemodynamically and
electrically stable. (Level of Evidence: C)