From the Departments of Imaging (Division of Nuclear Medicine) and
Medicine (Division of Cardiology), Cedars-Sinai Medical Center, and the
Department of Medicine, UCLA School of Medicine, Los Angeles, Calif, and the
Division of Cardiology, Department of Medicine, Duke University Medical
Center, Durham, NC. Dr Hachamovitch is currently at the Division of
Cardiology, New York (NY) Hospital-Cornell Medical Center. Dr Shaw is
currently at the Department of Medicine (Division of Cardiology), Emory
University, Atlanta, Ga.
Correspondence to Daniel S. Berman, MD, Cedars-Sinai Medical Center, Room A042, 8700 Beverly Blvd, Los Angeles, CA 90048.
Methods and Results—We identified 5183 consecutive patients
who underwent stress/rest SPECT and were followed up for the occurrence
of cardiac death or myocardial infarction. Over a mean follow up of
642±226 days, 119 cardiac deaths and 158 myocardial infarctions
occurred (3.0% cardiac death rate, 2.3% myocardial infarction rate).
Patients with normal scans were at low risk (
Conclusions—Myocardial perfusion SPECT yields incremental
prognostic information toward the identification of cardiac death.
Patients with mildly abnormal scans after exercise stress are at low
risk for cardiac death but intermediate risk for nonfatal myocardial
infarction and thus may benefit from a noninvasive strategy and may not
require invasive management.
Prospective, randomized clinical trials have shown several treatment
modalities to reduce cardiac mortality in selected patient
subsets.2 3 4 Recent trials of medical therapy
have demonstrated reductions in both fatal and nonfatal myocardial
infarction rates and cardiac death.5 6 7 8 Hence,
patients at risk for nonfatal myocardial infarction but not cardiac
death may benefit from aggressive medical management and not require
revascularization. If nuclear testing could
identify these patients, significant cost savings could be realized by
the potential reduction in referral to catheterization
and revascularization.
To this end, the goals of the present study were threefold: (1) to
define the incremental prognostic value of myocardial perfusion SPECT
for the prediction of future cardiac death; (2) to define the ability
of nuclear testing to risk stratify patients into three groups (low
risk for both myocardial infarction and cardiac death, intermediate to
high risk for myocardial infarction but low risk for cardiac death, and
at intermediate to high risk for both outcomes); and (3) to determine
the impact on the cost of testing if patients at low risk for cardiac
death but intermediate risk for nonfatal myocardial infarction were
treated medically and not referred to catheterization
as initial therapy.
Rest Thallium Imaging
Exercise Myocardial Perfusion Protocol
Adenosine Myocardial Perfusion Protocol
During both types of stress, blood pressure was measured and
recorded at rest, at the end of each stress stage, and at peak
stress. Maximal degree of ST-segment change at 80 milliseconds after
the J point of the ECG was measured and assessed as horizontal,
upsloping, or downsloping.
SPECT Acquisition Protocol
Image Interpretation
Patient Follow-up
Likelihood of Coronary Artery Disease
Statistical Analysis
The Cox proportional hazards model (BMDP version 7, program
2L16 ) was applied in a stepwise fashion to define
three models with cardiac death and hard events as separate end points:
(1) a prescan model (prescan likelihood of coronary artery
disease, history of coronary disease, type of stress
performed), (2) a nuclear scan model (in the absence of generally
accepted nuclear aggregate variables, we used the derived nuclear
variables shown in Table 2
Cumulative event-free survival rates as a function of time after the
index nuclear exercise test were calculated by use of the Kaplan-Meier
method and compared by use of the Mantel-Cox test (BMDP version 7,
1L16 17 ). Patients were first stratified by the
combination of prescan likelihood of coronary artery disease
(for patients with known coronary artery disease, a value of 1
was assigned) into low, intermediate, and high clinical risk subgroups
(prescan likelihood of coronary artery disease <0.15, 0.15 to
0.85, and >0.85, respectively). These subgroups were then further
stratified by the results of the nuclear scan. Incremental value was
defined as a statistically significant difference in the survival rates
of the subgroups after inclusion of nuclear information
(P<.05 by Mantel-Cox test).
Cost and Decision Analysis
Outcome Events
Univariable Analysis
With respect to nuclear variables (Table 2
Perfusion Scan Abnormalities and Outcomes
The distribution of events as a function of scan result also differed
with respect to the two end points. Of the cardiac deaths, 13% were in
normal scans and 10%, 15%, and 62% occurred in mildly, moderately,
and severely abnormal scans, respectively. With respect to myocardial
infarctions, 17% occurred in normal scans and 26%, 15%, and 42%
occurred in mildly, moderately, and severely abnormal scans,
respectively.
The rates of cardiac death in patients who underwent
revascularization early after testing compared with
those patients who were treated with medical therapy (Fig 4A
Incremental Value
The cardiac death and myocardial infarction rates in each prescan
likelihood of coronary artery disease category were further
stratified with respect to their risk of both cardiac death and
myocardial infarction by the nuclear scan result (Fig 6
Risk Adjusted Models: Role of Early Revascularization
Major Subgroup Analysis
Integrative Clinical History and Nuclear Decision Making
The superiority of the latter strategy was not altered in a sensitivity
analysis when cost and outcome rates were varied. Further, no
threshold was elucidated in which catheterization of
all abnormal studies would be equally as effective or more effective
than the moderate to severely abnormal catheterization
strategy.
Comparison With Previous Studies
Prevention of Myocardial Infarction Versus Prevention of
Cardiac Death
Although the large, multicenter randomized clinical trials failed to
show a reduction in infarction rates with surgical treatment, these
studies were not powered to detect this difference, nor was myocardial
infarction a primary end point. Furthermore, comparisons of infarction
rates between the surgical and medical arms of these studies are
obfuscated by the relatively high frequency of
perioperative myocardial infarctions. A number of
medical therapies have been shown to lower the frequency of both
cardiac death and myocardial infarction in specific patient groups and
to reduce the frequency of myocardial infarction in a general
population.5 6 7 8 If it would be possible to
identify patients at intermediate to high risk for myocardial
infarction but with a low risk of cardiac death (as shown
previously25 ), a unique window of opportunity for
treatment would exist.
Implications for the Use of Nuclear Testing
In the present study, patients with mildly abnormal scans after
exercise stress had a low risk of cardiac death but an intermediate
risk of nonfatal myocardial infarction. Because these patients are
unlikely to benefit from revascularization
procedures (particularly because both PTCA and CABG are associated with
mortality risks of
Study Limitations
Clinical and Statistical
Although myocardial infarction and cardiac death are related in many
cases, it is virtually impossible to accurately determine the exact
cause of cardiac death in each patient. The separation of these two
events may be problematic. However, numerous major,
well-accepted, prospective, randomized clinical trials have included
these end points as separate outcomes.2 3 4 5 6 7 8 With
respect to the identification of differential risk for myocardial
infarction compared with cardiac death, the pattern of risk we describe
for particular patient subgroups is not dissimilar to that previously
described with other modalities.25 Although the
prediction of cardiac death versus myocardial infarction in a
particular patient is difficult, it appears to be possible to identify
distinct populations in which one event is significantly more likely to
occur than the other. Finally, the analysis comparing medical
and early revascularization treatments after
nuclear testing is limited in that it is a nonrandomized
analysis; risk-adjusting these models in no way overcomes the
nonrandomized nature of this analysis.
Conclusions
Received June 10, 1997;
revision received September 29, 1997;
accepted October 9, 1997.
© 1998 American Heart Association, Inc.
Clinical Investigation and Reports
Incremental Prognostic Value of Myocardial Perfusion Single Photon Emission Computed Tomography for the Prediction of Cardiac Death
Differential Stratification for Risk of Cardiac Death and Myocardial Infarction
Abstract
Top
Abstract
Introduction
Methods
Results
Discussion
References
Background—The incremental
prognostic value of stress single photon emission computed tomography
(SPECT) for the prediction of cardiac death as an individual end point
and the implications for risk stratification are undefined. 
0.5%/y), and rates of
both outcomes increased significantly with worsening scan
abnormalities. Patients who underwent exercise stress and had mildly
abnormal scans had low rates of cardiac death but higher rates of
myocardial infarction (0.7%/y versus 2.6%/y; P<.05).
After adjustment for prescan information, scan results provided
incremental prognostic value toward the prediction of cardiac death.
The identification of patients at intermediate risk of nonfatal
myocardial infarction and low risk for cardiac death by SPECT may
result in significant cost savings when applied to a clinical testing
strategy.
Key Words: prognosis • tomography • perfusion
Introduction
Top
Abstract
Introduction
Methods
Results
Discussion
References
The application of
prognostic testing is based on the premise that patients identified as
being at high risk for adverse outcomes can be intervened on and the
natural history of their disease altered so that their subsequent risk
is reduced. Ideally, the prognostic utility of a test is defined with
respect to a particular outcome whose occurrence can be prevented by a
specific treatment, rather than being defined with respect to a
combination of end points that are treated dissimilarly. To date,
studies evaluating the prognostic value of myocardial perfusion single
photon emission computed tomography (SPECT) have used the combination
of myocardial infarction and cardiac death ("hard events") or hard
events and late revascularization as study end
points because of the relatively low frequency of serious adverse
outcomes and relatively small study cohorts.1
Because the treatment of patients for prevention of each of these
outcomes may differ, the application of prognostic nuclear testing to
patient management is potentially difficult.
Methods
Top
Abstract
Introduction
Methods
Results
Discussion
References
Study Population
We prospectively identified 5807 consecutive patients who
underwent dual isotope SPECT with either exercise or pharmacological
stress between January 1, 1991, and December 30, 1993, at Cedars-Sinai
Medical Center, excluding patients with significant valvular
heart disease or nonischemic
cardiomyopathies. Of this initial population, 269
patients were lost to follow-up, and 4 had missing data. The remaining
5534 patients with successful follow-up (95%) were included in this
study. The 351 patients revascularized in the first 60 days after
nuclear testing were excluded from the prognostic portion of the
analyses.9 10 Thus, the prognostic data
presented here are based on a subset of 5183 patients.
All patients underwent stress dual isotope myocardial perfusion
SPECT as previously described.11 Initially,
thallium-201 (2.5 to 3.5 mCi) was injected intravenously at
rest, with dose variation based on patient weight. Rest thallium
imaging was initiated 10 minutes after injection of the isotope.
Patients performed a symptom-limited treadmill exercise test
using standard protocols with a 12-lead ECG recording each
minute of exercise and continuous monitoring of leads aVF,
V1, and V5. At near-maximal
exercise, a 20- to 30-mCi dose of technetium-99m sestamibi
was injected (actual patient dose varied with patient weight), and
exercise continued for 1 minute after injection. SPECT was begun 30
minutes after isotope injection. Whenever possible, ß-blockers and
calcium channel antagonists were discontinued 48 hours
before testing, and nitrate compounds were discontinued at least 6
hours before testing.
Patients were instructed not to consume
caffeine-containing products for 24 hours before the test. After
rest thallium SPECT, pharmacological stress was performed by use of
adenosine infusion (140 µg ·
kg-1 · min-1 for 6
minutes). Sestamibi was injected at the end of the third minute of
infusion, and SPECT was initiated 
60 minutes after the end of the
adenosine infusion.12
SPECT studies were performed as previously described with a
circular 180° acquisition for 64 projections at 20 seconds per
projection.11 During imaging, two energy
windows were used for thallium-201, and a 15% window centered on the
140 keV peak was used for technetium-99m sestamibi.
Semiquantitative visual interpretation was performed with
short-axis and vertical long-axis myocardial tomograms divided into 20
segments for each study (Fig 1
). These
segments were assigned on six evenly spaced regions in the apical,
midventricular, and basal slices of the short-axis views
and two apical segments on the midventricular long-axis
slice.12 The scoring system used is described in
the legend to Fig 1. A summed stress score was obtained by adding the
scores of the 20 segments of the stress sestamibi
images.13 14 Summed stress scores <4 were
considered normal; between 4 to 8, mildly abnormal; 9 to 13, moderately
abnormal; and >13, severely abnormal. A summed rest score was obtained
by similarly adding the scores of the 20 segments of the rest thallium
images. The sum of the differences between each of the 20 segments on
the stress and rest images was defined as the summed difference score.
Each of these variables incorporate the extent and severity of
perfusion defects, both of which independently add prognostic
information.10
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Figure 1. Assignment of myocardial regions for scoring of
SPECT images.
Patient follow-up was performed by scripted telephone interview
by individuals blinded to the patients' test results. Events were
defined as either cardiac death as noted and confirmed by review of
death certificate and hospital chart or physician's records or
nonfatal myocardial infarction as evidenced by the appropriate
combination of symptoms, ECG, and enzyme changes. All patients included
in this report were followed for at least 1 year. The mean follow-up
interval was 642±226 days.
We used analysis of the prescan likelihood of
coronary artery disease as an aggregate descriptor of proven
prognostic importance based on Bayesian analysis of patient
data and calculated with CADENZA.15 For patients
undergoing pharmacological stress, only clinical and historical
information was considered, whereas for patients undergoing exercise
stress, the prescan likelihood of coronary disease included
clinical, historical, and exercise test information.
Comparisons between patient groups were performed by use of a
one-way ANOVA (with a Bonferroni correction where appropriate) for
continuous variables and a 
2 test for
categorical variables. Continuous variables were described as a
mean±SD. A value of P<.05 was considered statistically
significant. ), and (3) a combined model evaluating
the increase in prognostic information (model 2 adjusted for model 1).
The threshold for entry of variables into all models was
P<.05. A statistically significant increase in the global
2 of the model after the addition of the
nuclear variables defined incremental prognostic value.
View this table:
[in a new window]
Table 2. Patient Characteristics
Cost was calculated on the basis of Medicare hospital charges
(adjusted by cost-charge ratios) and physician billing
data.18 Median cost estimates and probability
values from the multivariable model were used in a decision model
to compare the cost savings (ie, marginal cost) provided by use of two
comparative strategies: catheterization of all patients
with an abnormal scan and catheterization of patients
with summed stress score >8. Cost-effectiveness was defined as change
in cost of strategy divided by change in hard event rate. Marginal cost
was calculated by comparing the difference in cost to the change in the
number of cardiac events identified between the two comparative
strategies. This decision model was performed with TREEAGE software and
included a threshold analysis, rollback, and a one-way
sensitivity analysis. Cost estimates were included in the model
and were varied by 30% to simulate the complexity of patient
presentation and to examine the probable input of bias in
the assumptions made in the model.19 Sensitivity
analysis was also performed by varying the cardiac death
rates.
Results
Top
Abstract
Introduction
Methods
Results
Discussion
References
Initial Patient Population
The 4104 patients in this study who underwent exercise stress and
the 1079 who underwent pharmacological stress are characterized in
Table 1. Comparison of the patients who
underwent exercise versus pharmacologic stress shows that the patients
who underwent the latter were older, more frequently had previous
cardiac events or procedures, had greater likelihoods of
coronary artery disease, had more severe and extensive scan
abnormalities, and had greater subsequent rates of adverse
outcomes.
View this table:
[in a new window]
Table 1. Patient Characteristics
Among the 5183 patients included in this study, 119 cardiac deaths
and 158 myocardial infarctions occurred (3.0% cardiac death rate,
2.3% myocardial infarction rate).
Revascularization within the first 60 days after
nuclear testing numbered 351 (181 coronary artery bypass graft
surgery [CABG] and 170 percutaneous transluminal
coronary angioplasty [PTCA]; 6.7% early
revascularization rate).
Descriptive patient characteristics and exercise and nuclear
variables in patients with or without events on follow-up are
presented in Table 2
. Comparison
of patients with cardiac death or myocardial infarction on follow-up
with those without shows that the former were older, had more cardiac
risk factors, more frequently had an abnormal rest ECG, had a greater
prescan likelihood of coronary disease, had more frequent
histories of previous myocardial infarction or
revascularization, and more frequently experienced
dyspnea as their presenting symptom (Table 2). In addition,
patients who had myocardial infarction on follow-up more frequently had
angina and less frequently were asymptomatic at the time of
testing relative to patients with no event on follow-up. Of note, 59%
of patients who experienced cardiac death and 46% of patients who
experienced myocardial infarction did not experience anginal symptoms
at the time of their nuclear test. Compared with patients who had
myocardial infarction on follow-up, those who had cardiac death were
older and more frequently had an abnormal rest ECG. ), patients with events
on follow-up had more extensive and severe scan abnormalities with
respect to both fixed and reversible defects. Compared with patients
who had myocardial infarction on follow-up, those who had cardiac death
had more severe and extensive stress perfusion scan abnormalities
caused by more nonreversible defects but similar amounts of
ischemia.
The frequency of events per year of follow-up as a function of the
scan result is illustrated in Fig 2. The
rates of both cardiac death and myocardial infarction increased as a
function of scan result (both P<.001). In the mildly
abnormal scan category, a greater rate of myocardial infarction than
cardiac death was present (0.8%/y versus 2.7%/y, respectively;
P<.05). When examined by the type of stress performed (Fig 3A and 3B), a significant increase in the
rates of myocardial infarction and cardiac death occurred as a function
of scan result (both P<.001). In the mildly abnormal scan
category, a significantly greater rate of myocardial infarction than
cardiac death occurred in the exercise stress group. No such difference
was found in the pharmacological stress group, possibly because of the
small number of patients (n=223). The rate of cardiac death per year in
patients with severely abnormal scans was significantly greater in
patients who underwent adenosine stress compared with exercise
stress (P<.01).
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Figure 2. Rates of cardiac death (open bars) and myocardial
infarction (solid bars) per year as a function of scan result. The
numbers are shown underneath the columns. *Statistically
significant increase as a function of scan result. **Statistically
significant increase in rate of myocardial infarction vs cardiac death
within scan category.
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Figure 3. Rates of cardiac death (open bars) and myocardial
infarction (solid bars) per year as a function of scan result in
patients undergoing (A) adenosine and (B) exercise stress. The
numbers for each subgroup are shown underneath the columns.
*Statistically significant increase as a function of scan result.
**Statistically significant increase in rate of myocardial infarction
vs cardiac death within scan category (P<.05). NL
indicates normal; ABNL, abnormal; MOD, moderately; and SEV,
severely. ) was significantly lower in patients
with severely abnormal scans (summed stress score >13). There was a
significant increase in the rate of cardiac death as a function of scan
abnormality in patients undergoing medical therapy that was not
present in patients undergoing early
revascularization. The rates of myocardial
infarction were similar in all abnormal scan categories; the exception
to this was the moderately abnormal scan group in which there were an
inadequate number of patients for adequate comparison (Fig 4B).
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Figure 4. Rates of (A) cardiac death and (B) myocardial
infarction per year as a function of scan result. Solid bars
represent patients undergoing initial medical therapy after
nuclear testing; open bars represent patients undergoing
revascularization early after nuclear testing. *
P<.01 vs patients undergoing
revascularization early after nuclear testing;
**P<.001 within patients treated with medical therapy
after nuclear testing. Abbreviations as in Fig 3 .
Significant information was contained in the model containing
clinical, historical, and exercise data and the model containing
nuclear variables alone (Fig 5).
Significant increases in global 2
(P<.00001) occurred after adjustment for the nuclear data
for prescan information, including the type of stress performed.
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Figure 5. Results of Cox proportional hazards
analysis. Prescan variables include the prescan likelihood
of coronary artery disease, history of coronary artery
disease, and type of stress used. *P<.00001 for gain in
2.). Patients with both normal and mildly
abnormal scans had low cardiac death rates (<1% per year of
follow-up), whereas moderately to severely abnormal scans had
intermediate to high rates in all clinical risk categories. Patients
with normal scans had low rates of myocardial infarction per year of
follow-up in all clinical risk categories (Table 4). The rates of
myocardial infarction in the mildly abnormal scan group were >1%/y
and increased in the moderately to severely abnormal scan groups in all
clinical risk categories. Risk-adjusted survival also revealed low risk
for cardiac death in normal and mildly abnormal scan groups but low
risk for combined events only in the normal scan group (Fig 7).
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Figure 6. Nuclear stratification by Kaplan-Meier
analysis.
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Table 4. Comparative Costs of Clinical Strategies in Patients
Undergoing Exercise Stress
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Figure 7. Risk-adjusted survival as a function of scan
result using (A) cardiac death and (B) hard events as an end point.
P<.00001 across scan results for both end points.
After adjustment for clinical, exercise, and nuclear results, the
presence of early revascularization yielded further
significant increases in global 2
(P<.005) for the prediction of cardiac death. The
risk-adjusted survival curves for patients who underwent early
revascularization versus medical therapy based on
this analysis (Fig 8) reveal an
improved survival rate in patients who underwent
revascularization early after nuclear testing.
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Figure 8. Risk-adjusted survival in patients who
underwent revascularization early after nuclear
testing (solid line) versus medical therapy (dashed line). Mantel-Cox
P<.005.
As shown in Table 3, the pattern of
outcomes described above—low mortality rates in normal and mildly
abnormal scans, low myocardial infarction rates in normal scans, and
intermediate to high rates in abnormal scans—was present in a
number of subgroups examined.
View this table:
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Table 3. Rates of Cardiac Death and Myocardial Infarction by
Scan Result
Compared with a strategy in which all patients undergoing exercise
stress with abnormal scans are referred to
catheterization, a strategy referring only those
patients with moderately to severely abnormal scans to
catheterization resulted in a 33.5% total cost savings
(P<.001) with similar outcome rates (Table 4). Total cost savings of 34.7%, 35.1%,
and 26.8% could be accrued for low-, intermediate-, and high-risk
patients (P<.001). The marginal cost for the identification
of hard events using a strategy of catheterization in
all abnormal scans was $157 412 per hard event in patients with
intermediate clinical risk. The marginal cost was far greater for
identifying hard events in patients at low and high clinical risk.
Discussion
Top
Abstract
Introduction
Methods
Results
Discussion
References
We found that after consideration of all prescan patient
information, nuclear information provided statistical incremental
prognostic value toward the prediction of both myocardial infarction
and cardiac death. Statistically significant and clinically relevant
risk stratification was achieved by the nuclear test even after initial
stratification by prescan information. Patients with normal scans had
low rates of both outcomes, whereas patients with mildly abnormal scans
who underwent exercise stress were at intermediate risk for myocardial
infarction but low risk of cardiac death, and patients with moderately
or severely abnormal scans were at intermediate to high risk of both
myocardial infarction and cardiac death. A risk-adjusted comparison of
post–nuclear testing referral to early
revascularization versus medical therapy suggested
a survival advantage to the former, predominantly in patients with
severely abnormal scans. Finally, cost analysis reveals that
referral to catheterization only in those patients with
moderately to severely abnormal scans rather than all abnormal scans
after exercise stress would result in a 33.5% cost savings.
The current study is the first to be sufficiently powered to
examine differences in the rates of myocardial infarction and cardiac
death after stress perfusion testing. Although a number of previous
studies have demonstrated the incremental prognostic value of
myocardial perfusion SPECT over clinical and exercise
data,1 13 14 20 21 22 23 they all used either combined
hard events or total events (hard events or late
revascularization) as end points. Although the
results of radionuclide angiography have been assessed toward the end
point of cardiac death,24 no previous study has
assessed myocardial perfusion imaging toward this end point. Harris and
colleagues25 compared the rates of cardiac death
and myocardial infarction in 1214 catheterized patients treated
medically. In this study, patients with single-vessel disease
experienced predominantly nonfatal myocardial infarction as their
events, whereas patients with more extensive anatomic disease had
cardiac death as a larger proportions of their events.
Several large trials have demonstrated the superiority of CABG
over medical treatment for lowering cardiovascular
mortality in select subsets of patients with chronic coronary
artery disease.2 3 4 26 Recently, multivessel PTCA
and CABG have been shown to have similar short-term survival
rates.27 28 29 It should be emphasized, however,
that these randomized trials of PTCA and CABG dealt with a highly
selective group of patients in whom the Duke databank experience and
previous randomized trials would suggest very little benefit from
revascularization over medical therapy with respect
to survival would exist, although the impact on symptom relief would be
significant.
In this study, all patients with a low prescan likelihood of
coronary disease were at very low risk (<1% risk of either
outcome). Because of the excessive cost to identify the few events that
occurred (Table 4), these patients probably did not require nuclear
testing unless quality of life was an issue. Of note, one third of our
cohort fell into this low-risk category, as previously
described.13 14 The results of the present
study were unchanged when this low-risk group was excluded, as shown by
the results in patients with intermediate and high clinical risk that
paralleled the overall study results. 
1%) but would experience lowering of their risk
for myocardial infarction by medical treatment, referral to
catheterization and its accompanying costs may not be
needed if these patients' symptoms could be controlled by medical
therapy. Conversely, patients with severe and/or extensive scan
abnormalities are at significant risk of cardiac death and should
undergo further evaluation of their coronary anatomy.
Unfortunately, the rate of referral to catheterization
after nuclear testing has not been found to exceed 50% to 60% even in
those patients with the greatest underlying
risk.14 30 31
Technical
The SPECT studies used were interpreted by experienced observers
using a standardized, validated semiquantitative visual
method,11 12 13 14 a method that served as the basis
for the quantitative computer program developed in our
center32 ; thus, our results should be similar to
those obtained with quantification. Because the expertise of the
observers in this study limits the extrapolation of our results to
visual results from other centers, further studies using objective
quantitative methods for analysis of SPECT studies would be of
interest.
The patients in this study were typical of those referred to a
university-affiliated community hospital in a major urban area, and the
results of this study should be applicable to this setting. Because of
the expertise of our laboratory, it is possible that our findings may
not be applicable to all laboratories nationally.
Even after all clinical, historical and exercise information is
considered, myocardial perfusion SPECT yields incremental prognostic
information for prediction of both cardiac death and hard events.
Clinically relevant stratification was present with both exercise
and adenosine stress in intermediate- and high-clinical-risk
subgroups. This stratification revealed that patients with mildly
abnormal scans after exercise stress are at low risk for cardiac death
but intermediate risk for nonfatal myocardial infarction and thus may
benefit from medical management and may not require invasive
intervention.
Acknowledgments
This work was supported in part by a grant from
Dupont-Pharma.
Footnotes
This work was presented in part at the 45th Annual Scientific Sessions of the American College of Cardiology, Orlando, Fla, March 24–27, 1996.
References
Top
Abstract
Introduction
Methods
Results
Discussion
References
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 B. L. Gerber MR perfusion imaging. What will be its impact for detection of coronary disease in the future? Eur. Heart J., February 2, 2008; 29(4): 434 - 435. [Full Text] [PDF]
|
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|
|
C. Marcassa, J. J. Bax, F. Bengel, B. Hesse, C. L. Petersen, E. Reyes, R. Underwood, and on behalf of the European Council of Nuclear Cardi Clinical value, cost-effectiveness, and safety of myocardial perfusion scintigraphy: a position statement Eur. Heart J., February 2, 2008; 29(4): 557 - 563. [Abstract] [Full Text] [PDF]
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J. Schwitter, C. M. Wacker, A. C. van Rossum, M. Lombardi, N. Al-Saadi, H. Ahlstrom, T. Dill, H. B.W. Larsson, S. D. Flamm, M. Marquardt, et al. MR-IMPACT: comparison of perfusion-cardiac magnetic resonance with single-photon emission computed tomography for the detection of coronary artery disease in a multicentre, multivendor, randomized trial Eur. Heart J., February 2, 2008; 29(4): 480 - 489. [Abstract] [Full Text] [PDF]
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|
 |
|
 M. L. Goris, H. J. Zhu, and T. E. Robinson A Critical Discussion of Computer Analysis in Medical Imaging Proceedings of the ATS, August 1, 2007; 4(4): 347 - 349. [Abstract] [Full Text] [PDF]
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|
|
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J. C. Wu, F. M. Bengel, and S. S. Gambhir Cardiovascular Molecular Imaging Radiology, August 1, 2007; 244(2): 337 - 355. [Abstract] [Full Text] [PDF]
|
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 |
|
 O. Gaemperli, T. Schepis, I. Valenta, L. Husmann, H. Scheffel, V. Duerst, F. R. Eberli, T. F. Luscher, H. Alkadhi, and P. A. Kaufmann Cardiac Image Fusion from Stand-Alone SPECT and CT: Clinical Experience J. Nucl. Med., May 1, 2007; 48(5): 696 - 703. [Abstract] [Full Text] [PDF]
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L. J. Shaw, T. H. Marwick, D. S. Berman, S. Sawada, G. V. Heller, C. Vasey, and D. D. Miller Incremental cost-effectiveness of exercise echocardiography vs. SPECT imaging for the evaluation of stable chest pain Eur. Heart J., October 2, 2006; 27(20): 2448 - 2458. [Abstract] [Full Text] [PDF]
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 K. Yoshinaga, B. J.W. Chow, K. Williams, L. Chen, R. A. deKemp, L. Garrard, A. Lok-Tin Szeto, M. Aung, R. A. Davies, T. D. Ruddy, et al. What is the Prognostic Value of Myocardial Perfusion Imaging Using Rubidium-82 Positron Emission Tomography? J. Am. Coll. Cardiol., September 5, 2006; 48(5): 1029 - 1039. [Abstract] [Full Text] [PDF]
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D. S. Berman, R. Hachamovitch, L. J. Shaw, J. D. Friedman, S. W. Hayes, L. E.J. Thomson, D. S. Fieno, G. Germano, N. D. Wong, X. Kang, et al. Roles of Nuclear Cardiology, Cardiac Computed Tomography, and Cardiac Magnetic Resonance: Noninvasive Risk Stratification and a Conceptual Framework for the Selection of Noninvasive Imaging Tests in Patients with Known or Suspected Coronary Artery Disease J. Nucl. Med., July 1, 2006; 47(7): 1107 - 1118. [Abstract] [Full Text] [PDF]
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Authors/Task Force Members, K. Fox, M. A. A. Garcia, D. Ardissino, P. Buszman, P. G. Camici, F. Crea, C. Daly, G. De Backer, P. Hjemdahl, et al. Guidelines on the management of stable angina pectoris: executive summary: The Task Force on the Management of Stable Angina Pectoris of the European Society of Cardiology Eur. Heart J., June 1, 2006; 27(11): 1341 - 1381. [Full Text] [PDF]
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D. V. Anand, E. Lim, A. Lahiri, and J. J. Bax The role of non-invasive imaging in the risk stratification of asymptomatic diabetic subjects Eur. Heart J., April 2, 2006; 27(8): 905 - 912. |