Stress Testing: Choosing
the Right Test for your
Patients
Sanford J. Gips, M.D., FACC
Cardiovascular Associates of the
Delaware Valley
Choosing the Best Test
• What is the patient's pretest risk
of CHD?
• Exercise vs. Pharmacologic
• Imaging vs Exercise ECG only
• How accurate are the alternative
tests?
• Do special considerations make
one test more suitable in a
specific patient?
Exercise ECG Testing vs.
Pharmacologic
• Exercise documents workload
that induces ischemia
• Exercise Capacity and
Hemodynamic Response predict
prognosis independent of
ischemia on imaging
• Limited by resting ST changes,
LVH, LBBB, paced rhythm, WPW
EKG Criteria in Stress
Testing
Non-invasive Testing
Modalities
• Echocardiography
• Radionuclide Myocardial
Perfusion Imaging (Thallium,
Cardiolyte, Myoview)
• Positron Emission Tomo (PET)
• CT Angiography
Stress Echo Baseline
Stress Echo After Exercise
Radionuclide Imaging
Stress Echo vs.
Radionuclide Perfusion
• Echo
– Higher specificity
– More extensive evaluation of anatomy and
function
– Greater convenience, availability
– Lower cost
• Stress Perfusion
– Higher technical success rate
– Higher sensitivity-esp circ disease
– Better accuracy when multiple resting wall motion
abnormalities present
– More extensive published data for gauging
prognosis
Questions to consider when
ordering a stress test
• Pre-test probability of CAD
• Reason for ordering stress test
– Suspected CAD
– Known CAD to evaluate new
symptoms
– Known CAD to eval med rx
• Advantages and limitations of
different stress testing
modalities
Why is Pre-test Probability
Important
• Low pre-test probability (5%)
– PPV of +EST only 21%
• High pre-test probability (90%)
– PPV of +EST 98%, -EST still 83%
chance of CAD
• Intermed pre-test probab (50%)
– PPV of +EST 83, -EST decreases
likelihood to 36%
Orders on Chest Pain Pts
• Suspected CAD (r/o CAD/angina)
– Don’t order meds that will inhibit
ability to obtain adequate stress
test (B-blockers, non-DHP Ca++)
– Don’t order meds with high
toxic/therapeutic ratios for low risk
pts (Nitrates)
– Do order anti-hypertensive meds
(DHP Ca++, ACE-I, diuretics)
– Do order anti-platelet rx, anti-coag
Stress Testing in the
Setting of Known CAD
• Purpose in this case is assessing
adequacy of medical rx
• Continue cardiac meds
• Getting HR to >85% not always
necessary
Which Stress Test to
Order?
Which Stress Test to
Order?
• Exercise EKG is always preferable if
pt can exercise to >85% MPHR
• Pharmacologic if unable to exercise
to full capacity, LBBB, abnl ST, LVH,
WPW
• Dipyridimole or adenosine for most
pharmacologic stress
• Dobutamine only for active wheezing
or known prob with persantine
Which imaging modality
• To some degree it is your choice
• Nuc better if likely to have poor
echo windows or abnl baseline
LV function
• Echo better if time or radiation
are important considerations
• PET best for obese, most
sensitive
Markers of LM or 3-Vessel
CAD
• Hypotension
• Bradycardia
• Transient ischemic dilatation
(TID)
• Multiple wall motion abnorm or
cavity dilatation on echo
• Ventricular Tachycardia
Who do I send right to
cath?
• High pre-test probability and
classic symptoms
• Previously unknown abnormal
LV function
• Recurrent CP with recent
negative or equiv stress test
Take Home Messages
• Most hospitalized pts will receive
imaging stress testing
• Exercise EKG is preferable to
pharmacologic stress unless pt can’t
achieve target HR or has LBBB/pacer
• Avoid neg chronotropes if stress test
is to r/o CAD
Take Home Messages
• Nitroglycerin is the most overused,
toxic med in the hospital
• Discharge for elective stress testing
may be appropriate for low risk
patients
• Catheterization is more cost-effective
for high-risk patients or recurrent
chest pain despite negative studies