The 80 Lead ECG Body Surface Map: Can We Detect More STEMI Than with a 12 Lead ECG

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The 80 Lead ECG Body Surface MapCan We Detect
More STEMI Than with a 12 Lead ECG?

• James Hoekstra MD
• Professor and Chairman
• Department of Emergency Medicine

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James Hoekstra, MD Disclosure Statement
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Initial Chest Pain Assessment

• Risk determined in the ED by
• Assessment of anginal symptoms
• Physical examination
• CAD risk factors
• Cocaine/methamphetamine use
• Electrocardiogram
• Markers of Infarction/Ischemia

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Limitations of the 12-Lead ECG

• Posterior MI
• Right Sided MI
• High Lateral MI
• Inferior MI
• LBBB and STEMI
• In an all-comers CP population, 98 of ECGs are
  nondiagnostic

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TRITON subset analysis evaluated occurrence of
occult STEMI

• TRITONTIMI 38 evaluated prasugrel vs.
  clopidogrel in 13,608 patients undergoing PCI
• Follow up duration 6-15 months
• Post-hoc analysis 1,198 patients with isolated
  anterior precordial ST segment depression (gt1
  mm) on 12-lead ECG
• STEMI defined as TFG 0/1 and positive troponin

Gibson CM. Circulation. Vol 118, Suppl. 2, 2008,
presented at AHA, Nov, 2008.
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95 of occult STEMI were missed in TRITONsubset
analysis

• 26.2 (314/1198) of patients with isolated
  anterior precordial ST segment depression gt1mm
  had a STEMI, TFG 0/11
• 4.5 (14/314) of STEMIs were interpreted as
  STEMI by investigators1
• Median time to PCI for patients with STEMI was
  29.4 hours1
• No patient with an occluded artery had an ECG to
  PCI time lt 6 hours

1198 patients with isolated anterior precordial
ST segment depression1
1.Gibson CM. Circulation. Vol 118, Suppl. 2,
2008.
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CULPRIT ARTERY IN STEMI PATIENTS
n56
n106
n152
TFG 0/1 in culprit artery Positive cardiac
biomarkers
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Occult STEMI patients had higher 30-day rates of
Death/MI
Occult STEMI in TRITON subset analysis1
Increased death/MI in patients with occult STEMI1
1.Gibson CM. Circulation. Vol 118, Suppl. 2,
2008.
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The 80-Lead ECG and Body Surface Mapping

• More leads investigate more areas of the heart
• Mapping allows computer generated pictures of
  ischemic areas
• Computerized readings allow for more accurate
  interpretation

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The PRIME ECG Technology
Single-patient Disposable Vest

• Easily-applied, self-adhesive plastic strips
  containing 80 data collection points
• Strips allow analysis of the hearts electrical
  activity with 360 degrees of spatial resolution
• Data from the 80 leads are processed into 3-D
  color maps for easy visualization

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Placement of the 80 Leads Provides a
Comprehensive View of the Heart

• 64 anterior and 16 posterior leads
• Conventional V leads 1-6 are marked

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PRIME ECG Allows You to Investigate Data from
All 80 Leads

• View a single 10-second recording for leads of
  interest

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PRIME ECG Provides a 3-D, Color-coded,
Anatomically-referenced Visualization of the
Injury
ST-segment elevation and depression are
translated into colors Red ST elevation Blue
ST depression Green No deflection
3-D Color Representation of the 80-Lead ECG
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Interactive Algorithm Suggests Diagnosis
Algorithm Result on Presentation
Pop-up Displays Underlying ECG Trace and Value
Anterior
Posterior

• Data from the 80 leads are processed by an
  interactive algorithm that suggests findings and
  can provide important details necessary to
  achieve a timely and accurate diagnosis
• Represents an extension of conventional ECG
  technology, resulting in a fast learning curve
  with minimal training time

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PRIME ECG Detected More Acute MIs Without Loss
of Specificity
In a meta-analytic composite of three separate
studies, PRIME showed relative improvement of 53
and absolute improvement of 23 over the 12-lead
McClelland, n103 (2)
Owens, n294 (3)
Ornato, n481 (1)

• Pretest probability of MI 51
• 12-Lead sensitivity 45
• PRIME sensitivity 64
• Relative improvement 42
• Absolute improvement 19

• Pretest probability of MI 62
• 12-Lead sensitivity 57
• PRIME sensitivity 80
• Relative improvement 42
• Absolute improvement 24

• Pretest probability of MI 22
• 12-Lead sensitivity 25
• PRIME sensitivity 34
• Relative improvement 33
• Absolute improvement 8

(1) Ornato JP, et al. Amer J Cardiol.
200239(5)332A (2) McClelland AJ, et al. Amer J
Cardiol. 200392252-257 (3) Owens CG, et al. J
Electrocardiol. 200437223-232
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The OCCULT MI Trial Design

• Multicenter prospective observational trial of
  80-lead mapping ECG versus 12 lead ECG
• 12 academic EDs, 1830 patients
• Moderate-to-high risk chest pain
• Clinicians blinded to result of 80L, treatment by
  standard of care
• Outcomes Door to Sheath Time and MACE in
  patients with STEMI by 80-lead-only versus STEMI
  by 12 lead ECG

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OCCULT MI 12-lead STEMI Population
1,830 patients enrolled
91 diagnosed as STEMI by site final diagnosis
1,739 not diagnosed as STEMI
84 underwent cardiac catheterization and had DTST
available
7 did not undergo cardiac catheterization 2
patients were DNR and aggressive medical measures
were withheld 1 refused cardiac
catheterization 1 deemed not to be a candidate
for cardiac catheterization 1 patient had GI
bleed and was monitored in the CCU 1 patient
expired prior to cardiac catheterization 1
patient treated conservatively due to normal
echocardiogram
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OCCULT MI 80L-only STEMI Population
1,830 patients enrolled
316 Troponin positive
1500 Troponin negative 14 missing
75 site-determined STEMI
241 not site-determined STEMI
210 with evaluable 80-lead PRIME ECG
27 with inevaluable 80-lead PRIME ECG 4 missing
25 PRIME-only STEMI 14 with DTST data
available 11 did not undergo cardiac
catheterization
185 NOT PRIME only STEMI
Tn positive defined as peak level over site
normal range, precath
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OCCULT MI Outcomes Cath Strategy Angiography
Door to Sheath Time
12L n84 80L, n14
plt0.0001
1002

92
Min

56
54
(median, minutes)
Revascularization 89 vs 78, p0.48
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OCCULT MI Clinical Outcomes
p0.45
12.5

8.0
Peak TnI 19.7 versus 10.3 ng/dl, p0.37
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OCCULT MI Conclusions

• 80 lead map ECG identifies 27.5 higher number of
  STEMI patients than 12 lead ECG
• 80 lead-only STEMI patients received conservative
  and significantly delayed catheterization
  strategy
• 80 lead-only STEMI patients have clinical and
  angiographic outcomes similar to 12 lead STEMI
• The 80 lead ECG identifies a patient population
  which may benefit from more aggressive care

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Who is Eligible for PRIME ECG?

• High risk patients, ongoing pain
• Abnormal, but nondiagnostic ECG
• ST Depression (25 missed STEMI)
• LBBB
• Known CAD, PCI, High TIMI Score
• Elevated Tn

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Summary

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• The 80-lead technology increases the sensitivity
  and specificity of the ECG for MI
• The PRIME system allows for ease of ECG
  acquisition in clinical care
• OCCULT MI trial confirms that PRIME can
• identify a high risk patient that may benefit
• from more aggressive therapy.