J Cardiol 2004 Sep; 44（3）: 101 – 111

Improved
Stratificationof
Perioperative Cardiac Risk inPatients Undergoing Noncardiac
Surgery Using New Indices of
Dobutamine Stress Echocardiography
TomokoYOKOSHIMA, MD

Hiroshi

HONMA, MD

Yoshiki KUSAMA, MD, FJCC
Kazuo

MUNAKATA, MD,FJCC

Teruo TAKANO, MD, FJCC
Kazuhiro NAKANISHI, MD＊
Abstract ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
Objectives. Prediction of perioperative cardiac events associated with noncardiac surgery remains difficult in patients whose functional capacity cannot be evaluated by exercise testing. Dobutamine stressechocardiography（DSE）has been used in these patients to improve risk stratification, but the results ofstandard DSE provide only a binary index of risk（positive or negative）. Two new semiquantitative indicesof DSE（semi-DSE）were retrospectively examined to determine the prediction of perioperative cardiac
events compared to standard DSE.
Methods and Results. Clinical assessment of cardiac risk factors and standard DSE were performed
safely in 122 consecutive patients（73 men, 49 women）
undergoing noncardiac surgery. Preoperative revascularization was performed in 12 patients. The perioperative cardiac events consisted of 2 deaths, 4 casesof heart failure, and 2 cases of angina pectoris. For the semi-DSE indices, the extent of ischemia wasindexed as the number of wall segments（SEG）displaying biphasic or worsening segmental wall-motion
score, and the severity of ischemia（SI）
was indexed as the sum of the differences in wall-motion scores
between peak stress and rest divided by the number of affected segments. The optimal cut-off values ofthese indices for predicting cardiac events were 4.0 for SEG and 1.0 for SI. The risk stratification was further refined by these indices（high-, moderate-, and low-risk groups）. The diagnostic accuracy of the semiDSE indices, evaluated by the area under the receiver operating characteristic curves, was better than thatof standard DSE（p ＜ 0.001）.
Conclusions. Semi-DSE may improve cardiac-event risk stratification compared to standard DSE inpatients undergoing noncardiac surgery whose functional capacity cannot be evaluated by exercise stresstesting.
──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────J Cardiol 2004 Sep ; 44
（3）
: 101−111

Key Words
Echocardiography, transthoracic
Risk factors cardiac

INTRODUCTION
Guidelines for perioperative cardiovascular eval-Stress echocardiography dobutamine

uation of patients undergoing noncardiac surgery
were published in 19961）. These guidelines emphasize the importance of identifying and evaluating──────────────────────────────────────────────
日本医科大学 内科学第 1，＊麻酔科学 : 〒 113−8603 東京都文京区千駄木 1−1−5
The First Department of Internal Medicine and ＊ Department of Anesthesiology, Nippon Medical School, Tokyo
Address for correspondence : HONMA H, MD, The First Department of Internal Medicine, Nippon Medical School, Sendagi 1−1−5,
Bunkyo-ku, Tokyo 113−8603
Manuscript received April 26, 2004 ; revised July 5, 2004 ; accepted July 5, 2004

101

102

Yokoshima, Honma, Kusama et al

cardiac risk by reviewing the clinical predictors thatare based upon medical history, physical findings
and electrocardiography, the patient s functional
capacity, and the type of surgery scheduled.
However, how to assess the cardiac status or how to
predict perioperative cardiac events when thepatient cannot perform an exercise tolerance test
and the functional capacity remains unclear2,3）.
Patients who cannot exercise or can exercise
only submaximally account for about 40% of thewhole population in a stress-testing laboratory4）. In
this situation, dobutamine stress echocardiography（DSE）may be useful for clinical decision making,especially for the prediction of perioperative cardiac events 2,5,6）. However, few reports haveattempted to stratify perioperative cardiac risk withsemiquantitative analysis of DSE in patients undergoing noncardiac surgery.
The present study retrospectively assessed two
semiquantitative DSE（semi-DSE）indices of theextent and severity of cardiac ischemia for the prediction of perioperative cardiac events, and compared these indices with standard DSE.
SUBJECTS AND METHODS
Subjects
This study included 122 consecutive patients, 73
men and 49 women aged 48 to 90 years［mean age
68 ± 9（SD）years］, who were scheduled for noncardiac intermediate-risk surgery at Nippon
Medical School Hospital during the period from
November 1996 to March 2001. The patients hadintermediate predictors and underwent standard
DSE for cardiac evaluation because they wereunable to perform an exercise tolerance test. Theintermediate predictors were defined according to
the American College of Cardiology/American
Heart Association（ ACC/AHA）guidelines 1）andcomprised the following : mild angina pectoris,
prior myocardial infarction, compensated or priorcongestive heart failure and diabetes mellitus.
Thirty eight patients had a history of coronary
artery disease, 83 patients had suspected coronary
artery disease, and one had a history of chronic
heart failure. Noncardiac intermediate-risk surgery
was performed for gastric cancer in 32 patients,
colon cancer in 25, cholecystitis or cholelithiasis in
15, orthopedic surgery in 20, cancer of the liver,bile duct or pancreas in 5, urogenital cancer in 5,
gynecological cancer in 5, head and neck cancer in
4, and benign abdominal disease in the remaining

11.
Clinical risk factors were determined from the
medical history, physical examination findings, and12-lead electrocardiography. After obtaining
informed consent, the patients underwent standard
DSE. Treatment with β-blocking agents was discontinued for at least 24 hr before DSE.
Dobutamine stress echocardiography
The DSE protocol was reported previously7）. We
used a commercially available echocardiographysystem（SONOS 5500, Philips Medical Systems）
with a 2.5-MHz transducer. Infusion of dobutamine
was started at 5μg ・ kg − 1 ・ min − 1 and wasincreased stepwise to 10, 20, 30, or 40μg ・
kg − 1 ・ min − 1. Atropine（ 5 mg）was given intravenously in patients who did not achieve 85% of
their age-predicted maximal heart rate and who had
no symptoms or signs of ischemia. The criteria for
stopping this test included : development of new orworsening segmental wall motion abnormalities
determined by continuous echocardiographic monitoring, achievement of 85% of the target heart rate,
ST segment depression ＞− 2 mm on the electrocardiogram, development of chest pain or symptoms
suggestive of myocardial ischemia associated withnew or worsening segmental wall motion abnormalities, delivery of the maximum dose of dobutamine（40μg ・ kg − 1 ・ min − 1）and administrationof atropine, development of severe hypotension（systolic blood pressure ＜ 90 mmHg）or severe
hypertension（systolic blood pressure ＞ 220 mmHg）,
and development of significant ventricular arrhythmia.
All echocardiographic images were recorded onvideotape, digitally obtained on-line, and edited inquad-screen cineloop format with simultaneous display of the resting, low-dose, peak-dose, and recovery stages. According to the recommendation of theAmerican Society of Echocardiography8）, the left
ventricle was divided into 17 segments and the segmental wall motion was scored on a 7-point scaleby visual evaluation : − 1 ＝ hyperkinesis, 0 ＝ normal, 1 ＝ mild hypokinesis, 2 ＝ moderate hypokinesis, 3 ＝ severe hypokinesis, 4 ＝ akinesis, and
5 ＝ dyskinesis. Hypokinesis was differentiated into
three grades according to the rate of increase ofwall thickness. The images were analyzed by two
observers, who were unaware of the clinical data,
angiographic findings and other echocardiographic
test results. The inter- and intraobserver variability
J Cardiol 2004 Sep; 44（3）: 101 – 111

Prediction of Perioperative Cardiac Riskof the results of analysis were 90%, and 96%,
respectively7）. The patterns of segmental response
to dobutamine were defined 9）: as Biphasic,
improvement of wall motion score ＞− 1 grade during the low-dose dobutamine study followed bydeterioration during the high-dose dobutaminestudy ; Worsening, deterioration of wall motion
during dobutamine infusion ; No change, absenceof improvement or worsening during dobutamine
infusion ; Sustained improvement, improvement
without deterioration of wall motion from low topeak dose of dobutamine. A positive finding for
dobutamine-atropine stress echocardiography was
declared only if at least two wall segments servedby the same coronary artery displayed wall motion
abnormalities of the biphasic or monophasic deteriorating type, as defined above.
Coronary angiography
Based on the results of standard DSE and clinicalrisk assessment, 38 patients underwent coronary
angiography. Percutaneous coronary intervention（PCI）or coronary artery bypass grafting was performed in patients who developed ischemia orbased on the recommendation of the attending cardiologist.
Detsky s index
Cardiac risk assessment was based on Detsky s
modified version of Goldman s cardiac risk
index10,11）for evaluation of assay sensitivity. The
following eight items were assessed : past historyof coronary artery disease, symptoms of coronary
artery disease, pulmonary edema, valvular heartdisease, arrhythmia, general condition, age, andemergency versus elective surgery.
Semi-DSE indices
Two semiquantitative indices were created retrospectively, the first to reflect the extent of myocardial ischemia（SEG）and the second to reflect theseverity of myocardial ischemia（SI）detected bystress echocardiography. SEG was defined as thenumber of segments exhibiting deteriorating wallmotion during stress at the stage of peak stress. SI
was defined as the summation of the difference ofthe scores（wall motion score at peak stress minus
wall motion score at rest）divided by the number ofsegments exhibiting deteriorating wall motion at
the peak stress. If SEG was zero, SI was defined aszero. The images were analyzed by two observers,
J Cardiol 2004 Sep; 44（3）: 101 – 111

103

who were unaware of the clinical data, angiographic findings and other echocardiographic test results.
Perioperative cardiac events
Perioperative cardiac events were defined as
events during the operation plus events that
occurred within 1 month postoperatively, including
fatal arrhythmias, heart failure, angina pectoris,
myocardial infarction and cardiac death. The diagnosis of these events was based on the symptoms,
physical findings, chest radiography, 12-lead electrocardiography and cardiac enzyme levels.
Statistical analysis
Univariate analysis of categorical variables was
performed with the χ2 test and Fisher s exact test,
and continuous variables were analyzed byStudent s t-test. Sensitivity, specificity, positive
predictive value, negative predictive value, andaccuracy were obtained as usual. Stepwise logistic
regression was employed to identify predictors ofcardiac events. All variables, regardless of their significance in univariate analysis, were entered into
the multiple logistic regression analysis.
Differences were considered significant at p ＜0.05. Receiver operating characteristics（ ROC）
curves 12）were used to determine the optimal
cut-off point for prediction of cardiac events withsemi-DSE and to compare the efficacy of diagnostic tests. Statistical analysis was performed using
SPSS software（Release 10.0, SPSS Inc.）.
RESULTS
Perioperative outcome
Eight perioperative cardiac events occurred in
the 122 patients : 5 episodes of heart failure, 2 ofunstable angina and 1 of myocardial infarction. The
events occurred at mean 5.4 days postoperatively.
Two patients died, one of myocardial infarction andthe other of congestive heart failure followed bymultiple organ failure, but the other six patients
recovered with medical treatment（Table 1）.
Clinical characteristics and perioperative cardiac events
The clinical features and clinical test data of thepatients with and without perioperative cardiac
events are shown in Table 2. Univariate analysis
showed that the significant clinical predictors of
perioperative cardiac events were history of valvular heart disease（ p ＜ 0.05）, standard DSE（p ＜104

Yokoshima, Honma, Kusama et al

Table 1 Clinical characteristics of the patients with perioperative cardiac events
No.

Age
Sex
（yr）

Diagnosis

Clinical characteristics

CAG#9 : 90%#14 : 90%→50%（PTCA）

1

68

M

Prostate cancer

ECG abnormality

2

74

F

Gastric cancer

HT, COPD, CVA, AF Stenosis（−）

3

74

F

Uterine cancer

OMI, CRF

ND

LVEF
SEG
（%）
47

SI Cardiac events

5

1.40 Variant angina

63

4

1.75

CHF

59

10

1.10

CHF

6

1.67

CHF

4

70

F

Colon cancer

OMI, HL#3, 4 : 75%, #6 : 75%, #9 : 90%
63#10 : 75%, #12 : 90%, #13 : 90%, #14 : 75%

5

59

M

Femoral fracture

HT, DM, CRF

ND

54

9

1.56 AMI to death

6

68

F

Colon cancer

OMI, HL#2 : 100%, #6 : 75%, #11 : 100%→0%（Stent）49

6

1.00

#1 : 90%→25%（Stent）#13 : 90%→50%（PTCA）

71

4

2.25 CHF to death#1 : 75%, #7 : 75%

71

6

1.33

7

76

M

Colon cancer

ECG abnormality,
HL, DM

875

M

Laryngeal cancer

AP

AP

CHF

CAG＝coronary angiography ; LVEF＝left ventricular ejection fraction ; SEG＝number of segments ; SI＝score index ; M＝male ;F＝female ; ECG＝electrocardiography ; HT＝hypertension ; COPD＝chronic obstructive pulmonary disease ; CVA＝cerebrovascular
accident ; AF＝atrial fibrillation ; OMI＝old myocardial infarction ; HL＝hyperlipidemia ; DM＝diabetes mellitus ; CRF＝chronic
renal failure ; AP＝angina pectoris ; PTCA＝percutaneous transluminal coronary angioplasty ; ND＝not detectable ; CHF＝congestive
heart failure ; AMI＝acute myocardial infarction.

0.01）, SEG（p ＜ 0.01）
and SI（p ＜ 0.01）. Age, sex,
other features of the history, and Detsky s index did
not differ statistically in patients who had a cardiac
event from patients who did not. In addition, resting left ventricular ejection fraction, cardiac output,
and the ratio of peak early rapid filling velocity toatrial contraction velocity（E/A ratio）were not univariate predictors of perioperative cardiac events.
The maximum dosage of dobutamine, rate-pressure
product, duration of surgery, and hourly fluid balance were also not predictive.
Dobutamine stress echocardiography and clinical course
Of the 122 patients, 63 were positive by standard
DSE and 59 were negative（Fig. 1）. Among the 63
positive patients, 28 patients who had multiple cardiac risk factors and showed worsening of wallmotion at a low dose of dobutamine underwent
coronary angiography. Twenty-five of these 28
patients had significant coronary stenosis（＞ 75%）,
and 11 patients underwent preoperative PCI and
one patient underwent coronary artery bypass grafting（CABG）. Despite preoperative revascularization, 3 of these 11 patients suffered from postoperative cardiac events, and one patient died of multiple
organ failure that was preceded by heart failure.
Although the remaining 13 patients were not considered to be at risk based on clinical findings anddata, two who developed heart failure postoperatively had high SEG and SI（Table 1）. Among thethree patients who did not have coronary arterystenosis, one patient developed tachycardic atrial
fibrillation which precipitated heart failure that
could be controlled by medical therapy.
The other 35 patients, most of whom had no
symptoms, risk factors or past history, did notundergo coronary angiography despite the positive
standard DSE. Two of these 35 patients had cardiac
events, one case of postoperative heart failure andone of fatal acute myocardial infarction. Neither
patient had preoperative coronary angiography
because of chronic renal failure. However, thesetwo patients showed high score of SEG and SI withmaximum dosage of dobutamine.
Among the 59 patients who were negative bystandard DSE, 10 patients had a history of coronary
artery disease and underwent coronary angiography. One of these patients had a 75% coronary
artery stenosis, but cardiac function was maintainedby collateral vessels. These 10 patients underwent
surgery without any perioperative events. Amongthe 49 patients who did not undergo coronary
angiography, none had perioperative cardiac events.
Throughout the standard DSE test, there were no
major adverse effects. Mild symptoms such as nausea, headache, chills, and palpitation developed in a
few patients, but the test was completed without
any other complications in all patients.
Semi-DSE indices
SEG and SI were significantly higher in patients
J Cardiol 2004 Sep; 44（3）: 101 – 111

Prediction of Perioperative Cardiac Risk

105

Table 2 Clinical characteristics and predictors of perioperative cardiac events in patients with orwithout events
Cardiac events（n＝8）

No cardiac events（n＝114）p value

Age（yr）

71±6

68±6

NS

Sex
（M/F）

4/4

69/45

NS

OMI（＜6M）

1（12.5）2（ 1.8）NS

OMI（＞6M）−
Angina pectoris

2（25）

44（38.6）

NS

6（75）

39（34.2）

NS

Heart failure06（ 5.3）NS

Valvular disease4（50）19（16.7）＜0.05

Arrhythmia

1（12.5）35（30.7）

NS

HT

6（75）

60（52.6）

NS

HL

3（37.5）44（38.6）

NS

HU

1（12.5）19（16.7）

NS

DM

2（25）

35（30.7）

NS

COPD

1（12.5）20（17.5）

NS

CVA

1（12.5）15（13.2）

NS

CRF

2（25）

6（ 5.3）

NS

Anemia2（25）34（29.8）

NS

Obesity3（37.5）36（31.6）

NS

Smoking3（37.5）60（52.6）NS

10.0±8.9

7.1±5.6

NS

History

Detsky s index
Echocardiography
LVEF
（%）

60±10

61±11

NS

E/A ratio

0.7±0.2

0.7±0.3

NS

Heart rate threshold（beats/min）

108.5±18.5119.2±19.6

NSIschemic threshold（%）

72.0±11.6

72.3±12.1

NS

Duration of surgery（min）

233±104

189±100

NS

Fluid balance（ml/hr）

430±229417±214NS

Surgery

DSE
8/0

58/56

＜0.0

28±13

26±10

NS

16,030±3,438

17,010±4,141

NS

SEG

6.3±2.2

2.2±2.9＜0.01

SI

1.5±0.4

0.7±0.8＜0.01Standard DSE（positive/negative）※
Max dose of DOB（μg・kg−1・min−1）
RPP（mmHg・beats・min−1）

Continuous values are mean±SD.（ ）: %.
※Positive indicates myocardial ischemia detected by standard DSE, negative indicates no myocardial ischemia bystandard DSE.
HU＝hyperuricemia ; E/A＝peak early rapid filling velocity/peak inflow velocity due to atrial contraction ; DSE＝dobutamine stress echocardiography ; DOB＝dobutamine ; RPP＝rate-pressure product. Other abbreviations as in
Table 1.

with perioperative cardiac events than in those
without perioperative cardiac events（ Table 2）.
Analysis of clinical and DSE variables using stepwise logistic regression revealed only two predictors of perioperative cardiac events, history of angiJ Cardiol 2004 Sep; 44（3）: 101 – 111

na and SEG（Table 3）. Moreover, the likelihood
ratio chi-square test statistic that resulted,χ2 ＝ 1.62
（p ＝ 0.20）, indicates that PCI was not a statistically significant confounder for Detsky s index andstandard DSE as predictors of cardiac events.

106

Yokoshima, Honma, Kusama et al

Fig. 1 Results of dobutamine stress echocardiography and preoperative coronary angiography
Flow chart of the procedure for prediction of perioperative cardiac events based on standard DSE and clinical assessment. Patient numbers correspond to those with cardiac events in Table 1.
CAG（＋）＝ coronary angiography performed ; CAG（−）＝ coronary angiography not performed ; CAD（＋）＝ findings of significant coronary artery disease ; CAD（−）＝ no findings of signficant coronary
artery disease ; PCI ＝ percutaneous coronary intervention ; CABG ＝ coronary artery bypass grafting.
Other abbreviation as in Table 2.

Table 3

Stepwise logistic regression analysis forpredictors of cardiac events
Odds ratio

95% CI

p valueAngina pectoris

7.3

1.09−48.7

0.041

SEG

1.5

1.11−1.90

0.007

CI＝confidence interval. Other abbreviation as in Table 1.

The optimal cut-off values for predicting perioperative cardiac events were defined by ROC curve
analysis as 4.0 for SEG and 1.0 for SI. According
to these SEG and SI values, the patients were divided into three groups. Among 35 patients with ahigh score for both SEG and SI（high-risk group）,
eight patients had perioperative cardiac events.
Among 30 patients with an intermediate score（moderate-risk group）and 57 with a low score（low-risk group）, no patient had a cardiac event（Table 4）. Detsky s index was significantly higher
in the high-risk group than in the low-risk group（p ＜ 0.01 ; Table 4）. Based on Detsky s index,
patients with a score of more than 10 were defined
as belonging to Detsky s high-risk group 10）.
Although 52 of the 122 patients were included in

Detsky s high-risk group, there were only threepatients with perioperative cardiac events. Four of
the remaining five patients with cardiac events had
a score of 5, and the other had a score of 0.
Diagnostic efficacies of standard DSE vs semiDSE
Sensitivity, specificity, positive predictive value,
negative predictive value, and accuracy of the two
tests for predicting perioperative cardiac events arelisted in Table 5. The diagnostic efficacies of thesetests for cardiac events were analyzed by the area
beneath the ROC curve. Semi-DSE was significantly better than standard DSE（p ＜ 0.001 ; Table 5）.
DISCUSSION
DSE has been considered to be a very useful
method to evaluate ischemia, but in most cases theresults of this test are expressed as only positive or
negative, so standard DSE cannot discriminate theextent or severity of ischemia. This study demonstrates that the semi-DSE indices for predicting
perioperative cardiac events can be used to differentiate high-risk patients from low-risk patients
more accurately than standard DSE. Furthermore,
J Cardiol 2004 Sep; 44（3）: 101 – 111

Prediction of Perioperative Cardiac Risk

107

Table 4 Clinical characteristics and predictors in patients grouped according to SEG and SI values
Moderate risk group Low risk group

High risk group（n＝35）（n＝30）（n＝57）＞4 & SI＞1.0
SEG−−＞4 & 1＞SI＞0
SEG−−
4＞SEG＞0

SEG＝SI＝0p value

8

0

0

＜0.01

Age（yr）

71±9

70±8

66±10

NS

Sex
（M/F）

25/10

20/10

28/19

NS

Detsky s index

10±7

8±5

5±5

＜0.01
＜0.01

Cardiac events

CAG

20

8

10

PCI/CAD
（＋）

10/18

2/7

0/1

TTE
LVEF
（%）

59±10

58±11

65±10

NS

E/A

0.7±0.4

0.6±0.2

0.7±0.2

NS

Duration（min）

177±113194±94200±97

NS

Fluid balance（ml/hr）

476±249431±187374±198

NS

23±11

25±10

28±9

NS

Operation

DSE
Max dose of DOB（μg・kg−1・min−1）
RPP（mmHg・beats・min ）17,181±4,007

15,223±3,795

17,707±4,096

NS

SEG

6.5±2.3

2.0±1.0

0

＜0.01

SI

1.6±0.6

1.2±0.3

0

＜0.01

−1

Continuous values are mean±SD.
TTE＝transthoracic echocardiography. Other abbreviations as in Tables 1, 2, Fig. 1.

Table 5 Diagnostic text index values of each method for cardiac events
specificity
（%）

PPV
（%）

NPV
（%）

100

52

13

100

76＊

23

MethodSensitivity（%）

Standard DSE
Semi-DSE

AUC

95% CI100

0.76

0.645−0.873

100

0.87＊

0.814−0.949＊

p＜0.001, standard DSE vs semi-DSE.
PPV＝positive predictive value ; NPV＝negative predictive value ; AUC＝area-under-the receiver operating
characteristic curve. Other abbreviations as in Tables 2, 3.

since DSE did not result in any fatal complicationsin this study, the semi-DSE indices can also be used
for perioperative cardiac risk stratification inpatients undergoing noncardiac intermediate risk
surgery.
Dobutamine stress echocardiography for preoperative evaluation
Several studies have suggested that wall motion
abnormalities and/or wall motion changes at a low
dose of dobutamine are especially important forpredicting the risk of cardiac event during major
vascular surgery2,3,5,6,13）. At present, an increasing
number of cases are scheduled for intermediate-risk
J Cardiol 2004 Sep; 44（3）: 101 – 111

surgery. Furthermore, there are many patients who
cannot undergo an exercise tolerance test due totheir poor general condition or physical disabilities.
In such patients, DSE has a few limitations, butalso has many advantages such as noninvasive,very safe, relatively inexpensive, and feasible inmost hospitals6,13）. In this series of patients, there
were no major adverse events with DSE and thetest was completed without any fatal complications.
Dobutamine stress echocardiography for noncardiac intermediate-risk surgery
Among the clinical characteristics, history of
valvular heart disease was the only predictor of

108

Yokoshima, Honma, Kusama et al

perioperative cardiac events by univariate analysis（Table 2）, but there were no remarkable characteristics in patients with valvular heart disease withpositive DSE. Other variables, such as Detsky s
index, were not significant predictors, in contrast to
previous reports5,6,13−15）. However, stepwise multiple regression analysis showed only history of angina pectoris and SEG were significant independent
predictors of cardiac events. This result suggeststhat some of the variables were influenced by eachother. Accordingly, the risk of perioperative cardiac
events appears to be difficult to identify without astress test.
Although standard DSE is one of the significant
predictors of perioperative cardiac events, it is difficult to perform coronary angiography in all patients
who have a positive standard DSE because standard
DSE identifies a lot of false positive cases andcoronary angiography is invasive and very costly.
This study showed that the SEG and SI indicesderived from semi-DSE are more accurate thanstandard DSE for the identification of high-riskpatients.
Prediction of perioperative cardiac events basedon both the severity and the extent of ischemia has
previously only been used to stratify risk prior to
major vascular surgery16）.
Can dobutamine stress echocardiography predict perioperative soft cardiac events?
DSE detects cardiac ischemia and myocardial
viability by assessing wall motion abnormalities
since the occurrence of such abnormalities are usually considered to be specific for myocardialischemia17,18）. This study evaluated both hard
events（myocardial infarction or cardiac death）andsoft events（ arrhythmia, heart failure, andischemia）. Among our six patients with soft events,
five were considered to have cardiac ischemia that
led to heart failure, but one did not have coronary
artery disease. Although these five patients had relatively good left ventricular ejection fraction atrest, the ischemia seemed to be induced postoperatively. The other patient might have had abnormalities in myocardial metabolism or perfusion without
any proximal stenotic coronary segments 19−21）,
because the SEG and SI were 4 and 1.75, respectively. Taking these results into account, there isalso a possibility that semi-DSE is a useful tool for
predicting soft events such as heart failure andarrhythmia based on myocardial ischemia.

Preoperative coronary revascularization
In this study, the decision to perform preoperative coronary revascularization was based on standard DSE and the patient s clinical status. In thehigh-risk group, eight patients did not undergo PCI
despite pre-existing coronary artery disease for thefollowing reasons : risk of the surgery was intermediate, coronary stenosis was not critical, and potential complications of PCI. In the moderate risk
group, two patients underwent PCI for criticalstenosis of distal lesions. Three of the 11 patients
who underwent PCI still suffered perioperative cardiac events.
Recently, patients who have undergone CABG
were reported to have a low rate of perioperative
cardiac events22−25）. In this study, only one patientunderwent CABG and did not have any perioperative cardiac events, although the interval fromCABG to noncardiac surgery was 56 days. There isa tendency for a lower incidence of cardiac death inpatients with PCI before noncardiac surgery26−28）,
However, there is some difficulty comparing
patients treated by PCI and patients without PCI inthis study, because this was an uncontrolled retrospective study and determination of prophylactic
preoperative PCI depended upon other factors in
addition to the results of standard DSE. Thus, theefficacy of prophylactic preoperative PCI for reducing untoward perioperative cardiac complications
remains unknown. The present study was too small
to determine which therapy was appropriate, andfurther studies will be necessary to assess the efficacy of coronary revascularization for reducing
perioperative cardiac events.
Limitations of this study
This study was retrospective, so we could not
avoid changes in management based on the discretion of the attending physicians, clinical findings,
and the results of standard DSE. This study was
also uncontrolled, so there are some difficulties ininterpreting the results and in assessing the usefulness of DSE for the prediction of perioperative cardiac events. As the result of many uncontrolled
variables, there were inconsistencies in the resultsof assessments of predictive efficacy of someindices. For example, SI was one of the most powerful predictors in the univariate analysis, whereas
history of angina pectoris and SEG were the only
significant predictors in the multivariate analysis.
Although objective interpretation of the results
J Cardiol 2004 Sep; 44（3）: 101 – 111

Prediction of Perioperative Cardiac Risk

of DSE is now of interest29）, DSE still involves subjective semiquantitative interpretation of echocardiographic images based on a scoring system. The
ischemic threshold during DSE is useful for prediction of perioperative cardiac events related to major
noncardiac surgery30）. The ischemic threshold isquantified by expressing the heart rate at whichischemia is first noted as a percentage of the agepredicted maximum. However, heart rate is alteredby physical conditioning or medical treatment, andthe ischemic threshold was not an accurate predictor in our study.
CONCLUSIONS

with poor general condition whose functional
capacity cannot be evaluated by exercise stress testing, DSE can be performed safely, and that thesemi-DSE indices, SEG and SI, can stratify the riskof cardiac events more accurately than standard
DSE. These new indices can be considered as
appropriate and highly sensitive parameters for predicting perioperative cardiac events.
Acknowledgements
We thank Tadaaki Ohno, MD, Ryou Munakata, MD, Masatomo
Yoshikawa, MD, and Tsuyako Matsuzaki, RN, for their assistancewith data management. We also acknowledge Kyoko Shigeno, PhD
for her great assistance in statistical analysis.

The present study demonstrated that in patients
要

約

ドブタミン負荷心エコー図法の新たな指標による
非心臓手術周術期心臓合併症発生リスクの層別化

目

横島

友子

本 間

博

草間

芳樹

宗像

一雄

高野

照夫

中西

一浩

的 : 運動負荷試験ができずに運動耐容能の評価が困難な症例では，周術期心臓合併症をいかに予測するかが問題となる．ドブタミン負荷心エコー図法（DSE）は，そのような症例に対して適応となるが，従来の評価法（standard DSE）では陽性か陰性かの判定のみであった．本研究では，後ろ向きに 2 つの新たな指標（semi-DSE）を用いて，周術期心臓合併症の検出率を従来の評価法と比較し検討した．
方法と結果 : 非心臓手術を受ける 122 例（男性 73 例，女性 49 例）に対して臨床上の心血管危険因子と standard DSE による評価を行った．術前，冠血行再建術は 12 例に施行されたが，周術期心臓合併症の発生は 8 例で，その内訳は，死亡 2 例，心不全 4 例，狭心症 2 例であった．虚血の拡がりを壁運動の悪化した区画数として表す SEG と，虚血の程度を壁運動が悪化した区画において負荷ピーク時から安静時の壁運動のスコアを差し引きその区画数で除した SI の 2 つを semi-DSE の指標とした．Semi-DSE の指標による後ろ向き評価では，周術期心臓合併症の発生を予測するカット・
オフ値は SEG 4.0，SI 1.0 であり，これにより高リスク群，中等度リスク群，低リスク群の 3 群に分類しえた．高リスク群には心臓合併症 8 例がすべて含まれる．Semi-DSE と standard DSE の診断精度を receiver operating characteristics 曲線の曲線下面積により比較すると，semi-DSE のほうが有意に検
出精度が高かった（p ＜ 0.001）．
結論 : 運動耐容能が不明で運動負荷試験の施行が困難な非心臓手術予定患者では，standard

DSE に比べて semi-DSE のほうが心臓合併症の発生リスクの層別化が可能となり，臨床上有用と考えられた．

J Cardiol 2004 Sep; 44（3）: 101−111

J Cardiol 2004 Sep; 44（3）: 101 – 111

109

110

Yokoshima, Honma, Kusama et al

References
1）Eagle KA, Brundage BH, Chaitman BR, Ewy GA, Fleisher
LA, Hertzer NR, Leppo JA, Ryan T, Schlant RC, Spencer
WH Ⅲ, Spittell JA Jr, Twiss RD, Ritchie JL, Cheitlin MD,
Gardner TJ, Garson A Jr, Lewis RP, Gibbons RJ,
O Rourke RA, Ryan TJ, for the Committee on
Perioperative Cardiovascular Evaluation for Noncardiac
Surgery : Guidelines for perioperative cardiovascular evaluation for noncardiac surgery : Report of the American
College of Cardiology/American Heart Association Task
Force on Practice Guidelines. Circulation 1996 ; 93 :
1278−1317
2）Lane RT, Sawada SG, Segar DS, Ryan T, Lalka SG,
Williams R, Brown SE, Armstrong WF, Feigenbaum H :Dobutamine stress echocardiography for assessment of cardiac risk before noncardiac surgery. Am J Cardiol 1991 ;68 : 976−977
3）Eichelberger JP, Schwarz KQ, Black ER, Green RM,
Ouriel K : Predictive value of dobutamine echocardiography just before noncardiac vascular surgery. Am J Cardiol
1993 ; 72 : 602−607
4）Marwick TH : Current status of non-invasive techniques forthe diagnosis of myocardial ischemia. Acta Clin Belg
1992 ; 47 : 1−5
5）Poldermans D, Fioretti PM, Forster T, Thomson IR,
Boersma E, el-Said ESM, du Bois NA, Roelandt JR, vanUrk H : Dobutamine stress echocardiography for assessment of perioperative cardiac risk in patients undergoing
major vascular surgery. Circulation 1993 ; 87 : 1506−15126）Lalka SG, Sawada SG, Dalsing MC, Cikrit DF, Sawchuk
AP, Kovacs RL, Segar DS, Ryan T, Feigenbaum H :Dobutamine stress echocardiography as a predictor of cardiac events associated with aortic surgery. J Vasc Surg
1992 ; 15 : 831−842
7）Honma H, Kusama Y, Matsuzaki T, Ohno T, Nishigaki R,
Munakata K, Kishida H, Takano T : Resting ultrasonic tissue characterization and dobutamine stress echocardiography for prediction of functional recovery in chronic left
ventricular ischemic dysfunction. Jpn Circ J 2001 ; 65:381−3888）Cerqueira MD, Weissman NJ, Dilsizian V, Jacobs AK,
Kaul S, Laskey WK, Pennell DJ, Rumberger JA, Ryan T,
Verani MS : Standardized myocardial segmentation andnomenclature for tomographic imaging of the heart : A
statement for healthcare professionals from the Cardiac
Imaging Committee of the Council on Clinical Cardiologyof the American Heart Association. Circulation 2002 ; 105 :539−5429）Afridi I, Kleiman NS, Raizner AE, Zoghbi WA :Dobutamine echocardiography in myocardial hibernation :Optimal dose and accuracy in predicting recovery of ventricular function after coronary angioplasty. Circulation
1995 ; 91 : 663−67010）Detsky AS, Abrams HB, Forbath N, Scott JG, Hilliard JR :Cardiac assessment for patients undergoing noncardiac
surgery : A multifactorial clinical risk index. Arch Intern
Med 1986 ; 146 : 2131−213411）Goldman L, Caldera DL, Nussbaum SR, Southwick FS,
Krogstad D, Murray B, Burke DS, O Malley TA, Goroll
AH, Caplan CH, Nolan J, Carabello B, Slater EE :Multifactorial index of cardiac risk in noncardiac surgicalprocedures. N Engl J Med 1977 ; 297 : 845−85012）Hanley JA, McNeil BJ : A method of comparing the areas
under receiver operating characteristic curves derived fromthe same cases. Radiology 1983 ; 148 : 839−843
13）Davila-Roman VG, Waggoner AD, Sicard GA, Geltman
EM, Schechtman KB, Perez JE : Dobutamine stressechocardiography predicts surgical outcome in patientswith an aortic aneurysm and peripheral vascular disease. J
Am Coll Cardiol 1993 ; 21 : 957−963
14）Steinberg EH, Madmon L, Patel CP, Sedlis SP, Kronzon I,
Cohen JL : Long-term prognostic significance of dobutamine echocardiography in patients with suspected coronary
artery disease : Results of a 5-year follow-up study. J Am
Coll Cardiol 1997 ; 29 : 969−973
15）Mangano DT : Perioperative cardiac morbidity.
Anesthesiology 1990 ; 5 : 153−18416）Poldermans D, Arnese M, Fioretti PM, Salustri A, Boersma
E, Thomson IR, Roelandt JR, van Urk H : Improved cardiac risk stratification in major vascular surgery with dobutamine-atropine stress echocardiography. J Am Coll Cardiol
1995 ; 26 : 648−653
17）Marcovitz PA, Armstrong WF : Accuracy of dobutamine
stress echocardiography in detecting coronary artery disease. Am J Cardiol 1992 ; 69 : 1269−127318）Yasugi N, Koyanagi S, Ohzono K, Sakai K, Matsumoto T,
Sako S, Homma T, Azakami S, Hiroki T : Comparative
study of dobutamine stress echocardiography and dual single-photon emission computed tomography（thallium-201
and I-123 BMIPP）for assessing myocardial viability after
acute myocardial infarction. Circ J 2002 ; 66 : 1132−113819）Bach DS, Muller DW, Gros BJ, Armstrong WF : False positive dobutamine stress echocardiograms : Characterizationof clinical, echocardiographic and angiographic findings. J
Am Coll Cardiol 1994 ; 24 : 928−933
20）Kawano H, Fujii H, Motoyama T, Kugiyama K, Ogawa H,
Yasue H : Myocardial ischemia due to coronary artery
spasm during dobutamine stress echocardiography. Am J
Cardiol 2000 ; 85 : 26−30
21）van den Heuvel AF, Bax JJ, Blanksma PK, Vaalburg W,
Crijns HJG, van Veldhuisen DJ : Abnormalities in myocardial contractility, metabolism and perfusion reserve in nonstenotic coronary segments in heart failure patients.
Cardiovasc Res 2002 ; 55 : 97−10322）Diehl JT, Cali RF, Hertzer NR, Beven EG : Complicationsof aortic reconstruction : An analysis of perioperative risk
factors in 557 patients. Ann Surg 1983 ; 197 : 49−56
23）Crawford ES, Morris GC Jr, Howell JF, Flynn WF,
Moorhead DT : Operative risk in patients with previous
coronary artery bypass. Ann Thorac Surg 1978 ; 26 : 215−
22124）Reul GJ Jr, Cooley DA, Duncan JM, Frazier OH, Ott DA,
Livesay JJ, Walker WE : The effect of coronary bypass on
the outcome of peripheral vascular operations in 1093
patients. J Vasc Surg 1986 ; 3 : 788−798
25）Nielsen JL, Page CP, Mann C, Schwesinger WH, Fountain
RL, Grover FL : Risk of major elective operation after
myocardial revascularization. Am J Surg 1992 ; 164 : 423−
42626）Allen JR, Helling TS, Hartzler GO : Operative procedures
not involving the heart after percutaneous transluminal

J Cardiol 2004 Sep; 44（3）: 101 – 111

Prediction of Perioperative Cardiac Risk

coronary angioplasty. Surg Gynecol Obstet 1991 ; 173 :285−28827）Huber KC, Evans MA, Bresnahan JF, Gibbons RJ, Holmes
DR Jr : Outcome of noncardiac operations in patients withsevere coronary artery disease successfully treated preoperatively with coronary angioplasty. Mayo Clin Proc 1992 ;
67 : 15−2128）Elmore JR, Hallet JW Jr, Gibbons RJ, Naessens JM, Bower
TC, Cherry KJ, Gloviczki P, Pairolero PC : Myocardial
revascularization before abdominal aortic aneurysmorrha-

J Cardiol 2004 Sep; 44（3）: 101 – 111

111

phy : Effect of coronary angioplasty. Mayo Clin Proc
1993 ; 68 : 637−64129）Takeuchi M, Yoshitani H, Miyazaki C, Haruki N, Otani S,
Sakamoto K, Yoshikawa J : Color kinesis during contrastenhanced dobutamine stress echocardiography : Feasibility
and applicability. Circ J 2003 ; 67 : 49−53
30）Torres MR, Short L, Baglin T, Case C, Gibbs H, Marwick
TH : Usefulness of clinical risk markers and ischemic
threshold to stratify risk in patients undergoing major noncardiac surgery. Am J Cardiol 2002 ; 90 : 238−242