Download Heart Failure - MCE Conferences

The Evaluation Of Ischemia
Case
• A 58 year old woman with diabetes and
hypertension presents with symptoms of
chronic chest pain. She reports that she can
walk about 4 blocks at a moderate pace
before developing squeezing chest pain,
shortness of breath and diaphoresis that
resolves with rest. An EKG in the office is
normal.
Case
• What is the best next step?
– Give her nitroglycerin sublingual and order a
treadmill stress test
– Refer for emergent angiography
– Order nuclear perfusion imaging
– Start ASA, BB, nitrates and monitor symptoms
Case
• During a treadmill stress test she exercises for 6
minutes and stops for chest discomfort. There are
infer-lateral ST depressions and nuclear imaging
shows a moderate sized reversible inferior defect and
no fixed defects. Which of the following is true?
– An angiogram followed by a stent will improve her
symptoms
– An angiogram follow by a stent with improve her
symptoms and prolong her life
– The patient should be sent for a CABG
– The patients medical therapy is not optimized
CAD And Angina: Significant Morbidity
and Mortality
•
•
•
•
•
•
•
•
Incidence 213/100,000 over 30
Lifetime risk: nearly 50% men, 32% women
13,200,000 with CAD, 6,500,000 with angina
7,200,000 post MI
53% of cardiovascular deaths
About 1 in 5 deaths in Americans
142.5 billion in 2006
11.1 million deaths worldwide by 2020
Libby. Braunwald’s Heart Disease. 8th Ed.
Cumulative Risk Of CAD Remains High
In Advanced Age
Lloyd-Jones. Lancet, 1999.
Angina
•
•
•
•
Chest or surrounding area caused by ischemia
Brought on by exertion
No associated with myocardial necrosis
Variety of discomfort
– Heavy, squeezing, pressure numb burning
• Location
– Substernal, arms, epigastric
• Anginal equivalents
– Dyspnea, faintness, fatigue
• Duration
– Better with rest or nitroglycerin
Not Angina
•
•
•
•
•
•
Pleuritic pain
Highly localized pain
Reproduced by movement
Duration very long or very short
Pain radiating to the lower extremities
Resolution more than 5-10 minutes after
nitrates or rest
Features That Decrease The Liklihood
Of Chest Pain Being Angina
Panju. JAMA, 1998.
Grading Angina
•
•
•
•
Class I: angina with strenuous activity
Class II: Slight limitation of ordinary activity
Class III: Marked limitation of ordinary activity
Class IV: Inability to do any physical activity or
angina at rest
Goldman. Circulation, 1981.
If It Is Not From The Heart….
Panju. JAMA, 1998.
Pathophysiology
• Regional myocardial ischemia
– Inadequate coronary blood flow
– Increased myocardial oxygen demand
Pathology of Atherosclerosis
Abrams. NEJM, 2005.
Factors Influencing Myocardial Oxygen
Supply and Demand
Libby. Braunwalds Heart Diseasea. 8th Ed.
Cardiovascular Risk Assessment
• Very high risk: no further estimation
– Established vascular disease
• Prior MI = 5-7x risk of recurrent MI
• Prior stroke= 2-3x risk of MI
• PVD = 4x risk of MI
– Diabetes
– Chronic kidney disease
– Hereditary dislipidemia
Canto. JAMA, 2003.
Risk of MI In Diabetics With No History
of CAD
Haffner. NEJM, 1998.
Why Assess Risk?
• Required for determination of medical
management
• More than 90% of CHD events in patients with
at least one risk factor
Risk Factors Associated With CAD
Yusuf. Lancet, 2004.
Framingham Risk Calculator
• Predicts risk of MI, CAD death and angina
– Low risk <10% risk in 10 years
– Intermediate 10-20% risk in 10 years
– High risk >20% in 10 years
Risk Assessment Tools: Framingham
Risk Calculator
Other Risk Calculators
• SCORE
• QRISK/QRISK 2
• Reynolds
Limitations Of Risk Calculation
• Falsely reassure patients with borderline risk
factors
• Does not consider lifetime risk
• Inability to account for effects of current
therapy
• Variation in severity of first event
• Variation by type of vascular disease
High Sensitivity CRP: Additive Value?
• Most patients with CAD have traditional risk
factors
• Unclear that CRP adds value in clinical practice
to traditional risk factors
Evaluation of Anginal Chest Pain
• Risk factor assessment
• Physical Examination
• Resting electrocardiogram
Asymptomatic Patients
• No need for stress testing
Non Invasive Stress Testing In
Symptomatic Patients
• Not useful for diagnosis of CAD in low risk or
high risk patients
• Useful if it will alter the planned management
strategy
Treadmill Stress Testing
• Useful in patients who can:
– Exercise on the treadmill adequately
– Have a interpretable EKG
Echo Stress Testing
• Can be performed with exercise or with
dobutamine
• Requires adequate echo visualization of the
heart
Nuclear Stress Testing
• Can be performed with exercise vasodilator
drugs
– Adenosine
– Dipyridamole
• Nuclear tracer is distributed in areas with
normal blood flow
• Requires contrast between areas of the heart
– False negatives with global ischemia
Sensitivity And Specificity
Of Stress Testing
Modality
Exercise ECG
Total
Sensitivity Specificity
[†]
[†]
Patients
24,047
0.68
0.77
Exercise SPECT
5,272
0.88
0.72
Adenosine SPECT
2,137
0.90
0.82
Exercise
echocardiography
2,788
0.85
0.81
Dobutamine
echocardiography
2,582
0.81
0.79
Gibbons. JACC, 2002.
High Risk Stress Test Features: Proceed
to Angiography
Gibbons. JACC, 2002.
Moderate And Low Risk Exercise
Testing
Gibbons. JACC, 2002.
CT Coronary Angiography
• Sensitity 90%
• Specificity 50%
• Not recommended for clinical use
Coronary Angiography
•
•
•
•
Gold standard for identification of significant CAD
Potential for revascularization
Cannot predict future site of plaque rupture and MI
Indications
–
–
–
–
Concern for left main or triple vessel disease
Poorly controlled symptoms
Ischemia at a low workload (5-6 mets)
Large or multiple defects or WMA
Assessment of Left Ventricular Function
• Echocardiography or nuclear study
• Necessary for strategizing the approach to
management
Treat Medical Conditions That Can
Worsen Ischemia
•
•
•
•
•
•
•
Anemia
Weight gain
Thyroid disease
Fever
Infections
Tachycardia
Cocaine
Necessary Lifestyle Modification
•
•
•
•
Diet
Exercise
Work activities
Leisure activities
– Avoidance of sudden exertion or isometric
exercise
• Sexual activity
– If equivalent level of activity is well tolerated
– Sildenafil cannot be taken with nitrates
Hypertension Management
• For adults, the risk of CAD double for every
increase of 20 mmHg over SBP 115
• Predisposes to vascular injury, accelerates
CAD, increases myocardial O2 demand and
worsens ischemia
• Goals of treatment
– Less than 140/90 or
– Less than 130/80 in DM or CKD
Smoking Cessation Decreases MI Risk
• Meta analysis of 20
studies
• 30% reduction in risk of
recurrent event in
patients who quit
smoking
• The most effective and
least expensive
approach
Critchley. JAMA, 2003.
Goals Of Medical Management In
Stable CAD
• Improve mortality and morbidity
• Manage symptoms
– Improve treadmill performance and time to ST
changes
• Prevent progression of atherosclerotic disease
• Requires adequate dosing and combination
approach
Aspirin
• Myocardial infarction reduction of 34-87%
• No difference in 81 vs 325 mg dose
• Clopidogrel may substitute for aspirin in
intolerant patients
Nitrates
• Nitrates
– Systemic vasodilator -> reduced LV wall stress
– Reduced myocardial oxygen demand
– Acute or chronic treatment
– Tolerance can
develop
– Improved ex
tolerance, time
to angina, and
ST changes
Chen. Proc Natl Acad Sci, 2002.
Beta Blockers
• Beta receptors
– B1: increase HR, contractility, AV
conduction
• cardioselective
– B2: vasodilation and
bronchodilation
– B3: catecholamine induced
thermogenesis
• Reduction in myocardial
oxygen demand
– Heart rate, contractility and wall
stress
• Improved mortality
– Prior MI or heart failure
ACE Inhibitors
• No benefit in the reduction
of ischemia
• Benefits shown in patients
with CAD and normal LV
function
• Improve endothelial
functioning
• HOPE Trial and EUROPA
– 20-22% RR ischemic event
HOPE Investigators. NEJM, 2000.
Cholesterol Lowering Improves
Mortality
NCEP. NHLBI, 2003.
Number Needed To Treat Is Low
NCEP. NHLBI, 2003.
LDL Target Based On Presence
of Risk Factors
After Reaching LDL Goals, Target NonHDL Cholesterol, Then HDL
• Total cholesterol – HDL= LDL + VLDL
• 30 mg/dl higher than LDL goal
• Treatment
– Statin followed by niacin or fibrates
• Low HDL: <40
• Treatment
– Lifestyle modification
– Niacin or fibrates
Ranolazine: Novel Antianginal
• No significant changes in heart rate or blood
pressure
• Reduction in calcium overload via inhibition of the
late Na current
• Improved exercise performance and time to ischemia
• Slight prolongation of the the QT interval, but no
association with TDP
• Contraindicated in pre-existing QT prolongation
Revascularization
• CABG or PCI
• No evidence for mortality reduction in
patients with stable angina and normal LV
function
Courage Trial: Initial Medical
Management vs PCI
• Unclear benefit of PCI in stable CAD
• Inclusion criteria
– At least one70% proximal stenosis, and objective ischemia
– At least one 80% stenosis and classic angina
• Exclusion criteria
–
–
–
–
–
–
Persistent CCS class IV angina
Markedly positive stress test
Refractory heart failure or cardiogenic shock
EF < 30%
Revascularization within 6 months
Anatomy unfavorable to PCI
• Randomized 1149-> PCI, 1138-> medical management
• Endpoints
– Death and nonfatal MI
– Death, MI, stroke or unstable angina
Courage Trial: No Difference Between
Initial PCI And Medical Management
Boden. NEJM, 2007.