Hemostasis Physiology and Clinical correlations by Dr Faiza.pdf
Kwong
1. Detecting Acute Coronary Syndrome in the Emergency
Department with Cardiac Magnetic Resonance Imaging
Raymond Y. Kwong MD
Co-Director, Cardiac Magnetic Resonance Imaging
Brigham and Women’s Hospital
Cardiology Grand Round
Beth Israel Deaconess Hospital
April 11th
, 2003
2. Acknowledgments
NHLBI
• Andrew E. Arai, MD
• Robert S. Balaban, PhD
• Anthony Aletras, PhD
• Adam Schussheim, MD
• Suresh Rekhraj, MD
• W. Patricia Ingkanisorn, MD
• Kenneth Rhoads, MD
Clinical Center
• Janice Davis, RN
• Grace Graninger, RN
Suburban Hospital
• Cardiology
Eugene Passamani, MD
• Emergency Room
Bob Rothstein, MD
• Radiology
Wayne Olan, MD
Susan O’Flahavan, RT
Paul LeBlanc, RT
Gian Serafini, RT
Chris Mancini, RT
Sarah Pirie, RT
3. Myocardial Infarction and Chest Pain
in the Emergency Room
• 1,100,000 MI per year in the US
About 1/3 will die from their MI *
• 6,200,000 people in the United States suffer
from angina
• 5,000,000 patients are evaluated in ER for
chest pain each year
American Heart Association.
1999 Heart and Stroke Statistical Update.
* Atherosclerosis Risk in Communities
(ARIC) study, NHLBI
4. The Spectrum of Chest Pain in the ER
Chest Pain
STEMI
NSTEMI
Unstable
Angina
ACS
Troponin
Non-cardiac
Chest Pain
Stable
Angina
5. Mortality of ER patients with chest pain
Pope et al. NEJM 2000; 342: 1163
6. Chest Pain in Emergency Department
LCE/NHLBI/NIH
ST Elevation
Acute MI
PTCA or
Thrombolytics
Intermediate
Likelihood CAD
Cardiac
Rx
Non-STE
MI
Unstable
Angina
Low Likelihood
CAD
Cardiac
Enzymes
12. Dipyridamole Stress MRI vs PET and QCA
Schwitter et al. Circ 2001; 103:2230
MRI Vs PET
Sensitivity 91%
Specificity 94%
MRI Vs QCA
Sensitivity 87%
Specificity 85%
13. Dipyridamole Stress First Pass Perfusion
Myocardial Perfusion Reserve Index
Al-Saadi et al
Circ 2000; 101:1379
MPR +
54
7
MPR -
6
35
Sensitivity 90%
Specificity 83%
CAD+
CAD -
14. 0
50
100
150
200
0 5 10 15 20
Time (s)
SignalIntensity
Width = τ 0
Fermi Function
Decay rate = κ
Flow
0
500
1000
1500
2000
2500
3000
0 5 10 15 20
Time (s)
SignalIntensity
Fermi Function Deconvolution
Estimates Absolute Myocardial Perfusion
(ml/min/g)
Input
Function
Myocardial
Enhancement
Mathematical
Model
16. Infarct Size: TTC vs MRI
Kim R. et al. Circulation. 1999;100:1992-2002
17. Correlation between MRI Infarct Size
and TTC Staining
Kim R. et al. Circulation. 1999;100:1992-2002
18. Kim RJ et al.
NEJM 2000;343:1445
Irreversible LV Dysfunction: Pre-intervention
After revascularization
Diastole Systole
Diastole Systole
Transmural Hyper
19. 0
20
40
60
80
100
0 1-25 26-50 51-75 76-100
0
20
40
60
80
100
0 1-25 26-50 51-75 76-100
Transmural Extent of Hyperenhancement Predicts
Recovery of Function
Transmural Extent of Hyperenhancement (%)
ContractileRecovery(%)
ContractileRecovery(%)
Kim RJ et al.
NEJM 2000;343:1445
All segments Akinetic or
Dyskinetic
20. PET vs MRI Viability
Klein et al. Circulation 2002; 105: 162
21. Microinfarction after PCI associated with
Minor Side Branch Occlusion
Ricciardi. Circulation 2001;103:2780-3
Patient 7: stent in the proximal LAD
and minor side-branch occlusion
Patient 2: stent in the mid-PDA
and minor side-branch occlusion
MI size = 0.7 to 12 g
22. Comparison of MRI and SPECT for
Detecting Myocardial Infarction
Wagner et al. Lancet 2003; 361: 374
23. Method: Acute Chest Pain Protocol
Localize Perfusion Function Viability
Time (min)0 10 20 30
24. Pilot phase
• To determine safety, feasibility, and logistic issues:
• 37 patients presenting with chest pain to the ER were studied.
– Patients were either from the ER or within 72 hours of admission to
the hospital.
» Well tolerated (1 failure to acquire any image due to
clasutophobia)
» 13 cases of AMI with a wide range of troponins all have
abnormal MRI
» Can perform MRI while receiving concurrent IV meds.
25. Case 1: 60 yo male
Day 2 post acute MI
Troponin 2X ULN
26.
27.
28.
29. Case 2: 80 yo female
No prior CAD
Chest pain with non-diagnostic EKG admitted 12
hours ago, small NQMI by troponin
30.
31. Case 2: 70 yo male
No prior CAD
Chest pain with non-diagnostic EKG admitted 12
hours ago, small NQMI by troponin
32.
33. Hypothesis
• We hypothesized that MRI could effectively
triage patients presenting with possible acute
coronary syndromes in the Emergency Room
34. Entry Criteria
• 30 minutes of chest pain compatible with
myocardial ischemia
• ECG not diagnostic of ST-elevation MI
Exclusions
• Pacemaker
• Defibrillator
• Other implanted active devices
• Brain aneurysm clips
35. Method
Prospective observational trial.
• Enrollment from 01/10/2000 to 09/27/2001
• Inclusion criteria:
• Chest pain > 30 minutes without obvious non-cardiac cause
• Exclusion criteria: any of the following
• ECG diagnostic of ST elevation acute myocardial infarction
• Ongoing active chest pain
• Hemodynamic instability
• Contraindications to MRI scanning
• > 12 hours since onset of last chest pain
.
36. Symptoms Suggestive of ACS
Noncardiac
diagnosis
Stable
Angina
Possible
ACS
Definite
ACS
ACC/AHA
Practice Guidelines
Unstable Angina
And NSTEMI
Circ 2000;102:1193
ST Elevation
MI
Confirmed ACS
ECG Not
Diagnostic
Troponin (-)
Serial
Studies
? Image
Stress
Test
- +
+
- + -
+
Unstable
Angina
ST or T
and/or
Troponin (+)
+
Non-ST
Elevation
MI
-
37. Method: Prospectively Defined Clinical Endpoints
Acute coronary syndrome (ACS):
Possible or definite ACS according to ACC/AHA
guidelines
38. Method: Prospectively Defined Clinical Endpoints
Acute coronary syndrome (ACS):
Possible or definite ACS according to ACC/AHA guidelines as
indicated by chest pain > 30 minutes (an entry criteria) AND
either angiographically significant CAD AND/OR significantly
abnormal stress testing performed during index hospitalization
or the subsequent 6- 8 week follow-up period.
Non-ST elevation acute myocardial infarction
(NSTEMI):
Abnormal troponin-I with a temporal pattern consistent with
acute MI and clinical evidence of coronary artery disease
(Coronary angiography, echo, or noninvasive imaging).
40. Method: Prospectively Defined Abnormal MRI
Abnormal defined by either:
• Regional wall motion abnormality (RWMA), or
• Myocardial hyperenhancement (Hyper).
Reading included perfusion images:
• Although independent diagnoses were not made using
perfusion alone, the perfusion images helped identify
abnormal regions.
42. Results: Study population
• 193 consecutive patients
• 11 refused to participate
• 21 excluded:
–6 hemodynamically unstable
–2 metallic implants
–3 large body size
–10 claustrophobia
• Remaining 161 formed the study cohort.
• All patients underwent conventional cardiac
workup as determined by the admitting
cardiologists or ER physician
43. 161 enrolled
•92 Male : 69 Female
•Age: 59 + 15 years old
•Average # of risk factors: 3.4
•History of prior MI: 25/161
•Median time since ER arrival:
2.7 hours (off hours cases excluded)
6.0 hours (off hours cases included)
•Average MRI scan duration: 38 + 12 minutes
Results: Study population
44. Patient Follow-up at 6 –8 weeks
161 patients
• 158 (98%) were successfully contacted at 6-8 week follow-up
• 3 were lost to follow-up: all troponin negative, 2 clinical low risk
with normal MRI and 1 high risk with abnormal MRI
45. Results: Demographic summary
ACS
(n = 25)
No ACS
(n = 136)
p value
Age (yr) 68 + 13 57 + 14 p = 0.0006
Men (%) 60 57 NS
CAD risk factors
Advanced Age (M>45, W>55) (%) 92 68 p = 0.03
Hypertension (%) 56 43 NS
Diabetes (%) 28 10 p < 0.001
Hypercholesterolemia (%) 64 47 NS
CAD in family (%) 32 42 NS
Hx. of smoking (%) 48 39 NS
Total number of CAD risk factors 4.2 3.2 p = 0.003
Characteristics of Chest Pain
Location
Substernal (%) 32 31 NS
Precordial (%) 24 18 NS
Quality
Crushing, heaviness, pressure or tightness (%) 56 54 NS
Radiation to neck/arm (%) 32 31 NS
Dyspnea, diaphoresis, or nausea (%) 32 40 NS
Previous angina (%) 40 12 p = 0.001
Average Chest Pain Score 8.4 7.5 NS ( p= 0.06)
TIMI risk score P < 0.00011.6 + 0.82.5 + 1.2
46. Table 1. Demographic Summary
ACS
n = 25
68 + 13
28%
40%
8.4
2.5 + 1.2
No ACS
n = 136
57 + 14
10%
12%
7.5
1.6 + 0.8
p value
0.0006
0.001
0.001
0.06
0.0001
Age
Diabetes
HTN
CP Score
TIMI Risk Score
Kwong et al. Circulation 2003; 107:531-7
54. D
S
End-systolic thickness (S) in mm
End-diastolic thickness (D) in mm
Absolute wall thickening in mm = S - D
Systolic diastolic ratio = S/D
Percent change in wall thickening (%) = (S-D)/D x 100%
Methods
56. 84 year old female with
Acute Non-ST Elevation MI
-20
0
20
40
60
80
100
120
140
160
0 10 20 30
Time (image number)
SignalIntensity
-50
0
50
100
150
200
250
300
350
400
450
500
0 10 20 30
Time (image number)
SIIntegral
33%
57. 68 year old female, with 2 hours CP, no risk
factors, nonspecific ECG, and normal troponin
58. 68 year old female, with 2 hours CP, no risk
factors, nonspecific ECG, and normal troponin
59. A 53 year old female with
3 days of intermittent rest chest pain
60. A 53 year old female with
3 days of intermittent rest chest pain
61. A 53 year old female with
3 days of intermittent rest chest pain
62. Adenosine Stress
Rest SSFP Adenosine Perfusion Gd Hyperenhancement
67 year old female with no prior CAD
+ DM, FMH, Tob, HTN
Troponin (-)
Cath: RCA 99%, Cx 99%, LAD 75%
63. Cardiac MRI Unit
The General Infirmary at Leeds
Diastolic Systolic
Perfusion
LAD/LCX RCA
Delayed image
MRI
conclusion:
significant
mid RCA
lesion
X-ray angiogram
64. Comprehensive Approach to Chest Pain:
MRI: Does It Have Any Role?
• ST Elevation MI
• Post-MI risk stratification
• Detection of residual ischemia
• Viability
• Non-ST elevation MI
• Same as ST elevation MI
• Also potential for more rapid diagnosis
• Unstable angina
• Early rest scan to detect evidence of recent ischemia
• Alternatively, scan after excluding MI with a stress test
65. Conclusions
• Use of cardiac MRI in the ER in assessment of patients
presenting with chest pain and a non-diagnostic ECG is
feasibility and safe.
• Cardiac MRI has high sensitivity and specificity for detecting
ACS, NSTEMI, and IHD in patients with chest pain, and
could provide useful diagnostic information beyond clinical
assessment.
• MRI parameters could be interpreted both qualitatively and
quantitatively with high accuracy in prediction of clinical
endpoints
• Further work is needed to differentiate acute from chronic
myocardial infarction and to improve scan efficiency.
66. Conclusions
• Add a slide:
The additional benefit of adenosine stress testing
Cost effectiveness of early patient triage translating into
savings in health care cost dollars
12 months prognostic data
68. 50 yo male lawyer, atypical chest pain
First troponin negative
69.
70.
71. 60 yo female presenting with an episode of prolonged
chest pain 24 hours ago, then another episode for several
minutes.
72.
73.
74.
75.
76.
77. 60 yo female presenting with “good story” of
unstable angina.
EKG: NSST changes
First troponin 3X ULN
78.
79.
80.
81. Cath during index hospitalization: NS stenosis
Uneventful at 6 weeks on no medications
Notas do Editor
Good afternoon,
In the first presentation of this session, Dr. Schussheim has presented the results of the pilot phase of our study.
I’ d now like to present the midterm results of the prospective phase of our study using cardiac MRI in the ER in evaluating patients presented with chest pain.
According to AHA statistics, there are over 1 million myocardial infarctions in this country per year and a third of them will die from it.
There are over 6 million people suffering from angina, and as a result, over 5 million cases of chest pain are evaluated in the emergency rooms each year. This illustrates the burden of chest pain syndromes to the health care system.
According to recent ACC/AHA guidelines, chest pain in the ER could be categorized into 3 risk groups.
10% of patients falls into the high risk group with acute ST elevation on admission EKG diagnostic of acute myocardial infarction. This group needs to be treated without delay and no further diagnostic testing is needed, therefore urgent assessment with MRI has very little role here.
In the groups with an intermediate to low clinical suspicion of acute coronary syndromes, at the time when they are diagnostically unknown, MRI may provide useful diagnostic information helpful in early risk stratification and treatment planning.
This slide describes the imaging sequences of the acute chest pain protocol:
Rapid localization sequence is followed by myocardial perfusion, function, and viability assessment in that order, over a period of approximately 40 minutes.
We hypothesized that MRI could effectively triage patients presented with possible acute coronary syndromes in the Emergency Room.
In the pilot phase we studied 37 patients from different risk groups to make sure we would have a representative sample of normal and abnormal cases in a small sample size.
In the prospective phase, at the time of this presentation, we have studied 121 patients over a 10 month period. These are patients presented to the ER with chest pain &gt; 30 minutes and
non-dx EKG
We hypothesized that MRI could effectively triage patients presented with possible acute coronary syndromes in the Emergency Room.
In the pilot phase we studied 37 patients from different risk groups to make sure we would have a representative sample of normal and abnormal cases in a small sample size.
In the prospective phase, at the time of this presentation, we have studied 121 patients over a 10 month period. These are patients presented to the ER with chest pain &gt; 30 minutes and
non-dx EKG
This slide illustrates the primary endpoints of our study.
The primary endpoints are acute myocardial infarction during index hospitalization, or significant CAD, re-hospitalization for MI, death, or stroke upon 30 day follow-up.
Acute myocardial infarction is defined by abnormal elevation of troponin levels concordant with findings on coronary angiography and/or clinical assessment.
This slide illustrates the primary endpoints of our study.
The primary endpoints are acute myocardial infarction during index hospitalization, or significant CAD, re-hospitalization for MI, death, or stroke upon 30 day follow-up.
Acute myocardial infarction is defined by abnormal elevation of troponin levels concordant with findings on coronary angiography and/or clinical assessment.
This slide illustrates the primary endpoints of our study.
The primary endpoints are acute myocardial infarction during index hospitalization, or significant CAD, re-hospitalization for MI, death, or stroke upon 30 day follow-up.
Acute myocardial infarction is defined by abnormal elevation of troponin levels concordant with findings on coronary angiography and/or clinical assessment.
This slide explains how we define a MRI study to be abnormal.
A cardiac MRI study is abnormal if any one of the following exists:
Regional wall motion abnormality regardless of other finding.
Myocardial hyperenhancement regardless of other finding.
Resting perfusion defect with congruent either RWMA or myocardial hyperenhancement.
All readings were done by the consensus of two cardiologists blinded to the endpoints of the studies.
Our scanner is only open from 7 to 7, Monday to Friday, so with the patients presented during offhours included, median time of MRI study from admission was 6 hours. However, that time is really about 2 hours when patients were presented during working hours.
Questions: what were your nine risk factors?
I retyped the slide. It looks like you are not using the slide layout function in powerpoint to help you deal with text alignment. Ask me sometime to show you what I mean.