Transcript Document

NONINVASIVE DIAGNOSIS IN
CORONARY ARTERY DISEASE
Nora Goldschlager, M.D.
MACP, FACC, FAHA, FHRS
Cardiology - San Francisco General Hospital
UCSF
Disclosures: None
CHEST PAIN
NOT DUE TO MYOCARDIAL ISCHEMIA
•
•
•
•
•
•
•
•
Pericarditis
Aortic dissection
Esophageal spasm/rupture/reflux
Peptic ulcer disease
Cervical spine disease
Pulmonary embolism
Musculoskeletal
Mediastinitis/pneumomediastinum
MYOCARDIAL ISCHEMIA NOT DUE TO
CORONARY ARTERY DISEASE
• Aortic valve disease (aortic stenosis)
• Hypertrophic cardiomyopathy (obstructive
and nonobstructive)
• Dilated cardiomyopathy
• Tachycardia
• Hypertension
• Coronary artery embolism
• Syndrome X (chest pain, and positive
treadmill, normal coronary arteries on
angiography)
• Coronary artery dissection
(e.g., Ao dissection, cocaine)
• Coronary arteritis
• Tako-tsubo cardiomyopathy
ASSESSMENT OF RISK FOR CORONARY
ARTERY DISEASE
• Is CAD known to be present (past angina, MI)?
• If CAD is not known to be present, what is the
risk profile? (lipids, blood pressure,
diabetes, family history, smoking)
• What are the symptoms and what brings them
on?
• Are there physical findings of acute ischemia?
of past MI?
• Are there ECG abnormalities, and are they
reversible?
• What is the response to sublingual
nitroglycerin?
ISCHEMIC CHEST PAIN SYNDROMES
• Stable effort angina
• Crescendo angina
• Acute coronary syndromes
- Unstable angina
- Acute MI: ST elevation, non ST elevation
WOMEN: PROBLEMS IN
MANAGEMENT OF CHD
• Significant gender gap in MI mortality
• Women, particularly younger women, have a
more adverse CHD prognosis than men
• Adjustment for disease severity, comorbidity
and treatment does not fully account for the
gap
• Women with normal or minimal CAD have an
adverse prognosis that is comparable to
diabetics
PATHOPHYSIOLOGY OF MYOCARDIAL
ISCHEMIA IN WOMEN
Outcomes Following
Normal/Minimal CAD at Cath
Outcomes Following
Significant CAD at Cath
• 29% perfusion
abnormality
• 65% persistent symptoms
at 5 years despite
conventional med Rx
• 10% required
rehospitalization for
symptoms
• Less obstructive
stenoses
• More myocardial
ischemia
• More unstable angina
and fewer transmural
infarcts
• More adverse prognosis
compared to men
WHY DO WOMEN HAVE A MORE
ADVERSE CHD PROGNOSIS?
• Not due to atypical presentation
• Not due to age
• Not due to comorbitidy
• Not due to gender gap in medical therapy
• Not due to more advanced angiographic CAD
• Differences in physiological vascular function
(endothelial and microvascular reactivity) are
likely (?partial) explanations
WISE STUDY: WOMEN’S
ISCHEMIA SYNDROME
EVALUATION
SHORT-TERM RISK OF DEATH OR NONFATAL MI
IN PATIENTS WITH UNSTABLE ANGINA - 1
HIGH
INTERMEDIATE
Hx
Acclerating
tempo of
ischemic sx
in 48 h
Prior MI, peripheral or
cerebrovascular disease,
or CABG/PCI, prior ASA use
Pain
Prolonged
ongoing (>
20 min) rest
pain
Prolonged (> 20 min) rest
angina, resolved, with
moderate or high
likelihood of CAD
Rest angina (<20 min) or
relieved with rest or SL NTG
Clinical Pulmonary
Age 70 yrs
edema, new
or worsening
MR, S3 or new/
worsening
rales,
hypotension,
bradycardia,
tachycardia
Age > 75 yrs
LOW
New onset or progressive
Class III or IV angina in
2 wks, with moderate or
high likelihood of CAD
SHORT-TERM RISK OF DEATH OR NONFATAL MI
IN PATIENTS WITH UNSTABLE ANGINA - 2
HIGH
ECG
INTERMEDIATE
Angina at rest T-wave inversion
with transient
ST-segment
changes
Pathological Q> 0.05 mV
waves
LOW
Normal or unchanged
during chest discomfort
BBB, new or
presumed new
Sustained VT
Cardiac Elevated
markers
Slightly elevated
Normal
TIMI RISK SCORE for UA/NSTEMI
Historical
POINTS
Age  65
1
3 CAD risk factors
1
(FHx, HTN, chol, DM,
smoker)
Known CAD (stenosis  50%) 1
ASA use in past 7 days
1
Presentation
Recent ( 24 h) severe angina
 cardiac markers
 0.5 mm ST 
1
1
1
RISK SCORE:
Total Points
(0-7)
14-DAY RISK OF CARDIAC EVENTS (%)
RISK
SCORE
0/1
2
3
4
5
DEATH/MI
DEATH/MI
URGENT REVASC
3
4
5
7
12
5
8
13
20
25
TIMI RISK SCORE for STEMI
Historical
Age  75
65-74
DM, HTN or angina
POINTS
3
2
1
RISK
SCORE
30-DAY MORTALITY (%)
Exam
SBP < 100 mmHg
HR > 100 bpm
Killip II-IV
Weight < 67 kg
3
2
2
1
0
1
2
6
0.8
1.6
2.2
4.4
Presentation
Anterior STE or LBBB
Time to Rx > 4 hrs
1
1
8
>8
27
36
RISK SCORE
Total points (0-14)
EVALUATION AND MANAGEMENT OF PATIENTS WITH SX SUGGESTIVE OF ACS
Possible ACS
Definite ACS
No ST 
Nondiagnostic ECG
Normal initial cardiac
markers
ST 
ST and/or T wave changes
Ongoing pain
Evaluate for
+ cardiac markers
reperfusion
Observe
FU at 4-8 hours
ECG, cardiac markers
No recurrent pain
- FU studies
Recurrent ischemic pain
or + FU studies:
Dx confirmed
Stress study to provoke ischemia
Evaluate LV function if ischemia
- : Potential diagnoses: nonischemic +:
Dx confirmed
CP, low-risk ACS
OP FU
ACC/AHA Guidelines 2002
Admit
Rx for ACS
BIOCHEMICAL CARDIAC MARKERS IN PATIENTS
SUSPECTED OF HAVING AN ACS - 1
Marker
Advantages
Troponin
Powerful tool Low sensitivity
for risk
in very early
stratification phase of MI
(< 6 h after
symptom onset)
Greater
sensitivity
and
specificity
Detection of
MI up to 2
weeks after
onset
Disadvantages
Limited ability
to detect late
minor reinfarction
Recommendation
Useful as a single test to
diagnose NSTEMI
(including minor damage)
BIOCHEMICAL CARDIAC MARKERS IN
PATIENTS SUSPECTED OF HAVING AN ACS - 2
Marker
Advantages
Disadvantages
Recommendation
CK-MB
Rapid, costefficient,
accurate
assays
 specificity in
Prior standard still
setting of
acceptable in most clinical
skeletal muscle circumstances
disease or injury
Ability to
detect early
reinfarction
low sensitivity
during very early
MI (< 6 h after sx
onset or later
(> 36 h) and for
minor
myocardial
damage
detectable by
troponins)
STENOSIS SEVERITY PRIOR TO MI
MI patients (n)
200
160
120
Stenosis prior to MI
> 70%
50-70%
< 50%
80
40
0
Ambrose
1998
Little
1968
Nobuyoshi
1991
Giroud
1992
All
PATHOPHYSIOLOGY OF ACUTE
CORONARY SYNDROMES 2006
Plaque Disruption / Erosion
Thrombus formation
& Embolization
Unstable
Angina
Non-ST
Elevation
MI
ST
Elevation
MI
Atherosclerosis: Traditional
vs. Contemporary Model
Traditional
Contemporary
Coronary remodeling concealing
extensive disease
Nissen, S. E. J Am Coll Cardiol 2003;41:103S-112S
Copyright ©2003 American College of Cardiology Foundation. Restrictions may apply.
CLINICAL PRESENTATION
OF MYOCARDIAL ISCHEMIA
• Chest pain/pressure/burning/
fullness/squeezing
• Epigastric discomfort/fullness/burning
• Jaw/throat/tooth pain
• Shoulder/back discomfort
• Breathlessness
• Fatigue
• Acute or worsening peripheral vascular
insufficiency
• Dizziness, syncope
THE OLDER THE PATIENT THE LESS
CLASSIC THE PRESENTATION
PHYSICAL EXAMINATION
DURING ACUTE MYOCARDIAL
ISCHEMIA / INFARCTION
• S3 gallop
•
•
•
•
•
•
Paradoxically split S2
Soft S1 (PR interval , dP/dt)
Mitral regurgitation murmur (transient)
Hypotension
Alterations in pulse volume
Pallor, diaphoresis, anxiety, tachycardia
(nonspecific)
ECG FINDINGS IN ACS
• ST-T abnormalities
- ST elevation
- ST depression
- Pseudonormalization
• Intraventricular conduction delay
• Transient Q waves
DURING
PAIN
AFTER
PAIN
Pseudonormalization
of T-wave inversion
during angina
PITFALLS IN THE
ECG DIAGNOSIS OF ACUTE MI
• Nonspecific ST/T-wave abnormalities
• Age of Q-waves (may not be known)
• Early repolarization pattern
• Paced ventricular rhythm
• Left bundle branch block
• Right bundle branch block: secondary
ST-T abnormalities in V1-3 can mimic
anterior-wall MI; tall R-waves in V1-2 can mimic
posterior-wall MI
• Nonspecific intraventricular
conduction delay with repolarization
abnormalities
• Atrial flutter with flutter waves  pseudo ST
 or 
• Double standardization
PERICARDITIS vs EARLY REPOLARIZATION
DIAGNOSIS OF ACUTE MI IN LBBB
• 1 mm ST segment change in same direction
as terminal QRS
• More than 5 mm ST elevation in direction
opposite to QRS
• Sgarbossa criteria (NEJM 1996;334:481)
- ST-elevation > 1 mm in lead with
concordant QRS complex
- ST-depression > 1 mm in leads
V1, V2 or V3
- ST-elevation > 5 mm in lead with
discordant QRS complex
5 points
3 points
2 points
Same patient, baseline ECG obtained 6 months earlier
PITFALLS IN THE ECG
DIAGNOSIS OF ACUTE MI: MI MIMICS
• Hyperkalemia
• Myocarditis
• Post-defibrillation
• Pericarditis with PR depression (scooped
ST segments)
• Early repolarization
• LVH
• Wide QRS complex tachycardias
• Left anterior fascicle block (poor R wave
progression; q V2-3, I, aVL)
• Left posterior fascicle block (q II, III, aVF)
• WPW patterns
• Pneumothorax with mediastinal shift
WPW MIMICKING
INFEROPOSTERIOR WALL MI
WPW MIMICKING INFERIOR WALL MI
HYPERKALEMIA vs ANTERIOR WALL MI
vs BRUGADA SYNDROME
Flutter - Pseudo ST elevation
PR
ST scoop
EFFECT ON OUTCOMES OF MISSING HIGH
RISK (ACUTE INJURY MI) ECG IN THE ED
• Missed Dx – 12% (5–15%)
• Effect on Rx (odds ratio)
No ASA – 2.13
No –blocker 1.85
• Mortality 7.9% ( vs 4.9% in ECG dx made correctly)
• Correlates of missed Dx
Advanced age
HF history
No chest pain
• ECG patterns in missed Dx
STE
8%
ST DEP
18%
T inversion 14%
Masoudi et al
Circulation 2006; 114:1565. N = 1684, 2 yr retrospective multicenter study
ESOPHAGEAL PAIN
More likely to:
- Continue for hours, rather than stuttering
- Be retrosternal, without lateral radiation
- Be nonexertional
- Interrupt sleep
- Be meal-related
- Be relieved with antacids
- Be associated with heartburn,
dysphagia, regurgitation
SOME REASONS TO PERFORM ECHO IN
PATIENTS WITH CHEST PAIN AND SUSPECTED
CAD
Suggestive of CAD
- Segmental wall motion abnormalities
(prior MI/ischemia)
- Reduced ejection fraction with WMA
(ischemic cardiomyopathy)
Not necessarily suggestive of CAD
- LVH (hypertension, hypertrophic
cardiomyopathy)
- Aortic valve stenosis
- Intimal flap of aortic dissection
- Reduced ejection fraction - no segmental WMA
- RVH
CLINICAL USES OF EXERCISE TESTS
• Evaluation of chest pain syndromes
- Effort angina: stable, crescendo
- Atypical chest pain, cardiac origin
- Atypical chest pain, noncardiac origin
• Assessment of effort tolerance
- Post-myocardial infarction
- Post-revascularization
- Valve disease
• Chronotropic competence
• Evaluation of rate control in AF
• Evaluation of Rx of CAD (medical,
surgical, post-PCI)
CLINICAL USES OF EXERCISE TESTS
• Evaluation of blood pressure Rx in
hypertension
• Detection of myocardial ischemia in pts at
high risk for CAD
• Exercise prescription and riskstratification post-MI
• Detection of exercise arrhythmias
- Due to myocardial ischemia
- Symptoms of cerebral hypoperfusion
with exercise
• Survivors of out-of-hospital cardiac arrest
ACC/AHA 2007 CLINICAL EXPERT
CONCENSUS DOCUMENT ON CT
CORONARY ARTERY CALCIUM SCORING
What is the role of coronary calcium measurement by
coronary CT scanning in asymptomatic patients with
intermediate CHD risk (between 10% and 20% 10-year
risk of estimated coronary events)?
It may be reasonable to consider use of CAC
measurement based on evidence that demonstrates
incremental risk prediction information in this patient
group. Such patients might be reclassified to a higher risk
status based on high CAC score, and subsequent patient
managementmay be modified.
What is the role of coronary calcium measurement by
CT scan in patients with low CHD risk (below 10%
10-year risk of estimated CHD events)?
Use of CAC measurement not recommended. This
patient group is similar to the “population screening”
scenario; screening of the general population is not
recommended.
ACC/AHA 2007
What is the role of coronary calcium measurement by
fast CT scan in asymptomatic patients with high CHD
risk (greater than 20% estimated 10-year risk of
estimated CHD events, or established coronary
disease, or other high-risk diagnoses)?
The Committee does not advise CAC measurement as
they are already candidates for intensive risk
reducing therapies.
ACC/AHA 2007
Is the evidence strong enough to reduce treatment
intensity in patients with calcium score = 0 in
patients who are intermediate risk before
coronary calcium score?
No evidence is available that allows a consensus.
Current standard recommendations for treatment
of intermediate risk patients should apply.
ACC/AHA 2007
Is there evidence that coronary calcium measurement
is better than other potentially competing tests in
intermediate risk patients for modifying
risk estimate?
CAC measurement has not been compared
to alternative approaches to risk assessment in
head-to-head studies. This question cannot be
adequately answered from available data.
ACC/AHA 2007
Should there be additional cardiac testing when a
patient is found to have high coronary calcium score
(e.g., greater than 400)?
Current practice guidelines indicate that patients
at high risk (e.g., diabetes) are candidates for intensive
preventive medical treatments. There is no clear
evidence that additional non-invasive testing in this
population will result in more appropriate selection of
treatments.
ACC/AHA 2007
Is there a role of CAC testing in patients with
atypical cardiac symptoms?
Patients at low risk of coronary disease by virtue of
atypical cardiac symptoms may benefit from CAC
testing to help in ruling out presence of obstructive
coronary disease. Other approaches are available,
and most of these have not been compared head-tohead with CAC.
ACC/AHA 2007
Can coronary calcium data collected to date be
generalized to specific patient populations?
CAC data are strongest for Caucasian, non-Hispanic
men. The Committee recommends caution in
extrapolating CAC data derived from studies in
white men to women and to ethnic minorities.
ACC/AHA 2007
What is the appropriate follow-up when an incidental
finding in the lungs or other non-cardiac tissues is
found on a fast coronary CT study?
Current radiology guidelines should be considered
when determining need for follow-up of incidental
findings.
ACC/AHA 2007
PRE TEST PROBABILITY OF CAD
• Patient population
– Asymptomatic (Framingham Risk Score)
•
Low risk - < 10% event rate in 10
years
•
Intermediate risk – 10-20% event rate
•
High risk - > 20% event rate
– Symptomatic (Diamond and Forrester –
NEJM 1979)
•
Non anginal chest pain
•
Atypical angina
•
Definite angina
CORONARY ARTERY CALCIUM
SCREENING: ESTIMATED RADIATION
DOSE AND CANCER RISK
• Median dose from a single scan – 2.3 mSv
Approx 250 chest x-rays
• 10 fold variation between scans
0.8 – 10.5 mSv
• Cancer risks for serial scans (q 5 years) for
middle aged persons (45 – 75 yrs)
42 excess cancers per 100,000 men
62 excess cancers per 100,000 women
LIMITATIONS OF CURRENT
CORONARY CALCIUM DATA
•
Highly selected populations,
– All patients referred to cath lab for
coronary angio
– High pre-test probability
•
Excluded technically inevaluable
patients from denominator
– Falsely inflates accuracy
•
No outcomes data