ORIGINAL ARTICLE
Economic evaluation of drug-eluting stents in Japan
Shunya Ikeda and Mia Kobayashi
Department of Health Policy and Management, Keio University School of Medicine, Tokyo, Japan(Received for publication on September 9, 2005)(Revised for publication on October 31, 2005)(Accepted for publication on November 24, 2005)

Abstract. Stenting with a sirolimus-eluting stent (SES) dramatically reduces the risk of restenosis
compared to bare metal stent (BMS) implantation. However, before SES can be widely adopted inclinical practice, it is essential to conduct an economic evaluation of this effective but expensive device.
Our study was undertaken to estimate the three-year cumulative medical costs of stenting using SES
compared to BMS. The data on clinical sequelae of stenting using BMS were derived from our previous
study, based on data collected from three Japanese hospitals. We estimated that the probability of
PTCA required for revascularization would be 0.224 times in SES implantation compared than in BMS
implantation based on the SIRIUS study result. The medical costs for procedures were obtained frompublished articles and were adjusted to the March 2005 level. Our simulation showed the expected
three-year cumulative medical cost per patient to be approximately ¥200,000 lower in the SES group(¥2,233,000) than in the BMS group (¥2,431,000). Sensitivity analyses with different presumptions
conﬁrmed that the economic advantage of SES over BMS was quite robust. We concluded that the useof SES would be a cost-saving option as compared with BMS implantation within the context of theJapanese healthcare system. (Keio J Med 55 (1): 15–22, March 2006)
Key words: sirolimus-eluting stent, medical cost, restenosisof restenosis is still as high as 10–40%, taking into consideration all types of lesions.1,2
Drug-eluting stents, i.e., stents coated with a drug
effective in the prevention of restenosis, have recently
been developed, and clinical trials have been carriedout. Among these, a sirolimus-eluting stent (SES),
coated with the immunosuppressive agent sirolimus,
has been evaluated in clinical trials conducted in foreign countries, and been shown to yield excellent
results. At present, SES is used in about 80 countries. In
Japan also, the SES was approved for use in the end of
March 2004.
The ﬁrst-in-man studies of SES in the world werecarried out in Sao Paulo (Brazil) on 30 subjects, and in
Rotterdam (the Netherlands) on 15 subjects. In thesestudies, none of the subjects developed restenosis during the follow-up period of 4–6 months.3 The long-term
outcome in patients treated with this type of stent wasalso excellent. Of the 30 patients enrolled in the study
at Sao Paulo, 28 were followed up for 2 years, and noneof these patients developed in-stent restenosis, and only

Introduction
Percutaneous coronary intervention (PCI) involves
insertion of a catheter into the narrowed region of thecoronary artery, followed by balloon dilatation or stentplacement. This procedure has been used for the treatment of ischemic heart disease in many countries
around the world. According to the Survey of Social
Medical Care Insurance Service 2002, during the 1month period of June 2002, a total of 8,201 patients
underwent PCI, including percutaneous transluminal
coronary angioplasty (PTCA), percutaneous coronary
thrombectomy, percutaneous coronary angioplasty witha percutaneous transluminal rotational atherectomy
catheter or percutaneous coronary stent placement. In
the past, PTCA was associated with a high incidence ofrestenosis of the affected coronary artery. While theintroduction of a coronary artery stent (hereafter simply
called ‘‘stent’’) has made it possible to reduce the incidence of restenosis to some degree, it has beenreported that even when a stent is used, the incidence

Reprint requests to: Dr. Shunya Ikeda, Department of Health Policy and Management, Keio University School of Medicine, 35 Shinanomachi,
Shinjuku-ku, Tokyo 160-8582, Japan, e-mail: ikeda@shunya.jp
15

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Ikeda S and Kobayashi M: Economic evaluation of drug-eluting stents

1 required re-intervention because of in-lesion restenosis.4
Later, a RAndomized study with the sirolimuseluting VElocity balloon-expandable stent in the treatment of patients with de novo native coronary artery
Lesions (RAVEL) was carried out on 238 patients at 19
facilities in Europe and Middle and South America,
comparing the sirolimus-eluting stent with a conventional stent (bare metal stent; BMS). In this study, theevent-free survival rate was signiﬁcantly higher in the
SES patient (94.1%) than in the BMS patient (70.9%).5
Only patients with 1-vessel lesions of the coronary
artery (2.5–3.5 mm in diameter), which can be coveredby an 18 mm-long stent, were enrolled in these studies.
It therefore was unknown whether or not this intervention would yield a similarly favorable outcome whenapplied to patients with other common lesions of thecoronary artery.
In the SIRolImUS-eluting bx velocity balloon expandable stent in the treatment of patients with de novo
native coronary artery lesions (SIRIUS) trial, arandomized comparison recently carried out at 53
facilities in the USA, 1,058 patients with various underlying diseases (diabetes mellitus in 26%, hyperlipidemia in 74%, hypertension in 68%, etc.) wereenrolled, and the coronary artery lesions were diverse,
including multiple-vessel lesions (42%) and longer
lesions (14.4 mm, on average). In this study also, theoutcome was found to be excellent in the SES patient.
Evaluation by angiography revealed that the incidence
of in-stent restenosis was 91% lower in the SES patient(3.2% vs. 35.4%, P < 0.001), and that of in-lesion
restenosis (including the 5 mm-wide areas at both endsof the stent) was 75% lower in the SES patient (8.9%
vs. 36.3%, P < 0.001).6
These results suggest that the use of SES might serve
as a radical solution for resolving the problem of restenosis which has been a major shortcoming of PCI.
However, before this treatment technique is adopted
more widely in clinical practice and covered by healthinsurance, it would be essential to conduct an evaluation of such therapy from the economic point of view.
Since the cost of developing and manufacturing SES ishigher than that of conventional stents, the cost of PCI
using SES is inevitably high (For example, in the United
Kingdom, an SES is sold at a price about 5 times as highas the price of a conventional stent.7 In the USA,
Cohen et al.8 reports an SES is sold for $2,900, while a
BMS is $900.). Such a high price can adversely affectsound management of medical resources.
In developed countries, increased medical costs due
to an aging of the population, advances in medical caretechnology, etc., have become a serious social issue.
Stemming the increase of medical costs to reasonablelevels has become a major political agenda in thesecountries, and various strategies have been taken towards this end. One such is that there is a growing trend
to analyze the cost-effectiveness of medical technology
to provide criteria for judging the appropriateness ofproviding insurance cover for a given medical service
and for determining the costs of medical care services.
For example, in the United Kingdom, the National
Institute for Clinical Excellence (NICE), an advisoryorganization on medical care technology under the National Health Service (NHS), is preparing the Technology Appraisal Guidance, primarily pertaining to highpriced pharmaceuticals and medical technology. This
guidance is planned to contain criteria for judging
whether or not a given medical technology can be recommended for insurance coverage on the basis of evaluation of clinical and economic evidence. The NICE
requested the industry to submit data on costeffectiveness of medicines as reference information for
preparing the guidance.9
In Japan also, the upward trend in medical costs andslump in the economy have pushed the National Health
Insurance (NHI) system to the brink of ﬁnancial collapse. Various measures to suppress medical costs havebeen introduced in this country to defuse this crisis. The
prices of medicines and medical materials under the
NHI have, as a rule, been reduced every 2 years. Furthermore, the reward for medical care was reduced
during the periodical review of the reward system forthe year 2002. In the year 2003, a new payment system
for the cost of inpatient care named ‘‘DPC (Diagnosis
Procedure Combination)’’ was introduced in university
hospitals and national centers. To facilitate efﬁcientutilization of medical resources under these circumstances, it would seem desirable to promote costeffectiveness analysis of medical technology and utilize
the ﬁndings as appropriate for policy adoption in Japan,
as in other developed countries.
The present study was undertaken to evaluate theeconomic impact of PCI using SES, considering its potential widespread use in Japan.
Methods
From the payer’s perspective, the 3-year cumulative
medical costs for patients who underwent PCI with SES
were analyzed, in comparison to PCI with BMS.
Basic analyses(1) Clinical results
The probability of target lesion revascularization(TLR) i.e., re-intervention or coronary artery bypass
grafting (CABG), being required in the BMS patient
was determined on the basis of data collected from 3
Japanese hospitals.10 It was found that the probability

Keio J Med 2006; 55 (1): 15–22
Table 1

Probability of TLR in the BMS Group

PTCA
CABG
myocardial infarction
death

Table 217
Table 3

1 year

1–2 years

2–3 years

28.0%
2.1%
1.0%
1.5%

1.5%
0.5%
2.0%
0.0%

1.0%
0.5%
2.0%
0.0%

Outcome of Treatment in the SIRIUS

PTCA
CABG
myocardial infarction
death

BMS group

SES group

p-value

19.2%
1.7%
3.4%
0.8%

4.3%
0.9%
3.0%
1.3%

<0.001
0.295
0.730
0.547

of PTCA being required within 1 year was 28.0%, thatwithin 1–2 years was 1.5%, and that within 2–3 years
was 1.0%. The probability of CABG being required
within 1 year, 1–2 years, and 2–3 years was 2.1%, 0.5%,
and 0.5%, respectively (Table 1).
The reported outcome of treatment in the SIRIUS
study on the 360th day is shown in Table 2.11 On thebasis of these data, we estimated that the probability of
PTCA being required would be 0.224 times higher in
the SES patient than in the BMS patient, and assumed
that the percent decrease in this probability observedon the 360th day would be maintained after the 360th
day.
In the SIRIUS study, there were no signiﬁcant interpatient differences in the percentage of cases needing
CABG, the incidence of myocardial infarction, or thedeath rate when the data on the 360th day were analyzed. Therefore, the incidence of myocardial infarction
and the death rate previously recorded for the BMS
patient in Japan (Table 110) were applied to the SES
patient of the present study.
(2) Data on medical expenses
The medical expenses in this study were used after
they were adjusted to the price levels prevailing as ofMarch 2005. The correction used the percent modiﬁcation of medical service fee (hereafter simply called‘‘modiﬁcation rate’’) effected in April 2000 (þ0.2%),
the modiﬁcation rate effected in April 2002 (2.7%),
and the modiﬁcation rate effected in April 2004
(1.05%). Since the amount paid for PTCA and stenting was markedly reduced, for reasons of price differences between Japan and foreign countries, the application of the overall modiﬁcation rate of the medical

Cost of PCI Using the BMS

BMS technicalchargecost of BMS
cost of balloon
cathetertechnical charge þBMS(1) þ balloon
catheter(1)other cost
total cost for
1-vessel lesions
technical charge þBMS(2) þ balloon
catheter(2)other cost
total cost for
2-vessel lesions
technical charge þBMS(3) þ balloon
catheter(3)other cost
total cost for
3-vessel lesions

price levels asof April 1998

price levels asof March 2005

difference after
modiﬁcation¥199,000¥228,000¥29,000¥338,000¥263,000¥318,000¥192,000¥20,000¥71,000¥800,000¥738,000¥62,000¥821,487¥1,621,487¥792,496¥1,530,496

¥28,991
C¥90,991¥1,401,000¥1,248,000¥153,000¥594,946¥1,995,946¥573,950¥1,821,950

¥20,996
C¥173,996¥2,002,000¥1,758,000

¥244,000¥924,849¥2,926,849¥892,210¥2,650,210

¥32,639
C¥276,639

service fee to these 2 services would lead to an excessive lag from the actual state. Therefore, the technicalcharge and material costs (costs of balloon and stent)
for PTCA and stenting were adjusted using the ofﬁcial
technical charge and material cost prevailing as ofMarch 2005. For the other medical expenses, the overall modiﬁcation rate of medical service fee was used forthe correction.
The costs of inpatient care in cases of PCI using the
BMS in the year 1998 were reported by Noda et al. tobe 1,621,487 Japanese yen (¥) for patients with 1-vessel
lesions, ¥1,995,946 for patients with 2-vessel lesions,and ¥2,926,849 for patients with 3-vessel lesions.12
These costs were adjusted to the price level as of March
2005 using the method mentioned above, to yield¥1,530,496 for patients with 1-vessel lesions, ¥1,821,950
for those with 2-vessel lesions, and ¥2,650,210 for thosewith 3-vessel lesions (Table 3). The average cost of rehabilitation at outpatient clinics was reported by Ikeda
et al. to be ¥9,600 in the year 1998.10 This amount was
adjusted to the price level using the modiﬁcation rate,to ¥9,261.
The cost of inpatient care in cases undergoing repeat
PTCA for restenosis was reported in the year 1998 by
Noda et al. to be ¥1,368,990 for 1-vessel lesions,18
Table 4

Ikeda S and Kobayashi M: Economic evaluation of drug-eluting stents
Cost of PTCA
price levels as price levels as difference afterof April 1998 of March 2005 modiﬁcation

PTCA technicalchargecost of balloon
catheter¥205,000¥228,000¥23,000¥263,000¥192,000¥71,000

technical charge þballoon catheter(1)other cost
total cost for
1-vessel lesions¥468,000¥420,000¥48,000¥900,990¥1,368,990¥869,193¥1,289,193

¥31,797
C¥79,797¥731,000¥612,000¥119,000¥876,228¥1,607,228¥845,305¥1,457,305

¥30,923
C¥149,923¥994,000¥804,000

¥190,000¥1,482,769¥2,476,769¥1,430,441¥2,234,441

¥52,328
C¥242,328

technical charge þballoon catheter(2)other cost
total cost for
2-vessel lesions
technical charge þballoon catheter(3)other cost
total cost for
3-vessel lesions¥1,607,228 for 2-vessel lesions, and ¥2,476,769 for 3vessel lesions.12 These costs were adjusted to the pricelevel as of March 2005 by the above-mentioned
method, to yield ¥1,289,193 for 1-vessel lesions,¥1,502,621 for 2-vessel lesions, and ¥2,301,589 for 3vessel lesions (Table 4). The average cost of rehabilitation of these patients at outpatient clinics reported forthe year 1998 by Ikeda et al. was ¥19,200,10 which was
adjusted to the costs as of 2005 by the medical service
fee modiﬁcation rate, to ¥18,522.
The percentages of 1-vessel, 2-vessel, and 3-vessel
lesions for which stenting with BMS, stenting with SES,
or PTCA for restenosis are applied were determined on
the basis of the number of cases undergoing elective
surgery (excluding cases of acute myocardial infarction)
at 143 facilities as reported by Shihara et al. (3,757 caseswith 1-vessel lesions, 2,283 cases with 2-vessel lesions,and 1,047 cases with 3-vessel lesions).13
The cost of inpatient care in patients undergoing
CABG in the year 1998 was reported by Noda et al. tobe ¥4,989,161 for 2-vessel lesions and ¥4,255,033 for
3-vessel lesions.12 These costs were adjusted by themodiﬁcation rate. Since the cost of inpatient care forpatients undergoing CABG for 1-vessel lesions had notbeen reported, ¥343,000 (the difference in the cost between 3-vessel and 2-vessel lesions) was deducted fromthe cost for 2-vessel lesions to yield the cost for 1-vessel
lesions. The percentages of 1-vessel, 2-vessel, and 3vessel lesions undergoing CABG were determined on

the basis of the number of cases undergoing elective
surgery (excluding cases of acute myocardial infarction)
at 62 facilities reported by Shigematsu et al. (455 caseswith 1-vessel lesions, 889 cases with 2-vessel lesions,and 400 cases with 3-vessel lesions).14 The average costof rehabilitation at outpatient clinics reported for thethe year 1998 by Ikeda et al. was ¥192,000, which was
adjusted by the modiﬁcation rate to ¥185,224.10
The average cost of treatment of myocardial infarction reported by Ikeda et al. for the the year 1998 of¥591,460 was adjusted by the modiﬁcation rate to¥570,587.10
The cost of an SES as of March 2005 (¥421,000/set)
was used in this study. The other costs of stenting using
SES were deemed to be equal to those of stenting using
BMS. It was assumed that the length of hospital stayand the incidence of complications at the ﬁrst admission
did not differ between the BMS patient and the SES
patient.
The analyses covered a 3-year period, and no discounts rate for time preference was incorporated.
Sensitivity analysis(1) Percentage of patients undergoing CABG for
restenosis
In the SIRIUS study, the percentage of patients who
underwent CABG on the 360th day of the initial stenting using the SES was 0.547 times that of the BMS
patient, although this difference was not statisticallysigniﬁcant.11 In the sensitivity analysis, therefore, thepercentage of patients undergoing CABG in the SES
patient was assumed to be 0.547 times that of the BMS
patient.
(2) Cost of inpatient care in patients undergoing CABG
Two reports, each from a single facility, were available concerning the cost of inpatient care for patients
undergoing CABG. Two analyses of sensitivity were
performed on the basis of these 2 reports.
In the ﬁrst, Okawa et al. reported that the cost of
inpatient care was ¥2,924,040 for CABG with cardiopulmonary bypass (on-pump CABG, ONCAB),¥1,693,650 for CABG without cardiopulmonary bypass(off-pump CABG, OPCAB), and ¥1,138,580 for minimally invasive direct coronary artery bypass grafting(MIDCAB).15
In the other, Tsuda et al. reported that the cost of
inpatient care was ¥3,243,000 for ONCAB and¥2,082,000 for OPCAB.16 Using these price data andthe results of the questionnaire survey at 262 facilities
conducted by the Japanese Association for Coronary
Artery Surgery in the year 2002 for 7,850 cases who
underwent ONCAB, 5,397 cases who underwent
OPCAB, and 231 cases who underwent MIDCAB, weKeio J Med 2006; 55 (1): 15–22

19

calculated the average cost of inpatient care for patients
undergoing CABG for restenosis.
(3) Time preference
Since there is no international consensus over the
discount rate to adjust time preference, we applied 2
discount rates to costs: (1) An annual discount of 3% inaccordance with the recommendation of the Washington Panel, USA,17 and (2) annual discount of 3.5% inaccordance with the guidelines of NICE, UK.18
Results
Base-case analyses
Table 5 shows the results of the base-case analyses.
The expected medical cost per patient during the ﬁrst
year was about ¥170,000 cheaper for the SES patient(¥2,155,000) than for the BMS patient (¥2,324,000). The
medical costs expected for the second and third years
were also lower for the SES patient than for the BMS
patient. The 3-year cumulative medical cost per patient
was about ¥200,000 cheaper for the SES patient(¥2,233,000) than for the BMS patient (¥2,431,000).
Figure 1 compares 3-year cumulative medical costs
specifying items. Although the cost of stenting itself in
SES patient was higher, as the number of PTCA for
restenosis decreased, 3-year cumulative medical cost
resulted lower.
The price of the SES set which would make the 3year cumulative medical cost equal to that for the BMS
patient was ¥543,694 (1.29 times the current price).

Fig. 1Three-year cumulative medical cost.

Table 6 Results of Sensitivity Analysis Based on the Assumption of
Decreased Percentage of Patients Undergoing CABG
expected medical cost
ﬁrst year

BMS¥2,287,000
patient
SES¥2,090,000
patient2-yearcumulative
second year medical
cost

expected
medicalcost forthird year

3-yearcumulative
medicalcost¥49,000¥2,336,000¥41,000¥2,377,000¥25,000¥2,114,000¥23,000¥2,137,000

Sensitivity analysis(1) Percentage of patients undergoing CABG for
restenosis
Table 6 shows the results of analysis based on theassumption that the percentage of patients undergoing
CABG for restenosis would decrease after stenting using the SES. The expected medical cost per patient
during the ﬁrst year was about ¥200,000 cheaper for the

Table 5Results of the Basic Analyses
expected medical cost
ﬁrst year

BMS¥2,324,000
patient
SES¥2,155,000
patient2-yearcumulative
second year medical
cost

expected
medicalcost forthird year

3-yearcumulative
medicalcost¥57,000¥2,381,000¥50,000¥2,431,000¥40,000¥2,195,000¥38,000¥2,233,000

SES patient (¥2,090,000) than in the BMS patient(¥2,287,000). The medical costs for the second and thirdyears were about 50% lower for the SES patient thanin the BMS patient. The 3-year cumulative medical cost
per patient was further reduced by the use of SES as
compared to the results from the basic analysis:¥2,167,000 for the SES patient and ¥2,431,000 for the
BMS patient.
(2) Cost of inpatient care in patients undergoing CABG
Table 7 shows the results of the sensitivity analysis
conducted under different presumptions regarding thecost of inpatient care for patients undergoing CABG.
Under all presumptions, the cost for the ﬁrst year, the2-year cumulative cost and the 3-year cumulative costwere smaller for the SES than for the BMS patient.
(3) Time preference
Table 8 shows the results of sensitivity analysis conducted under varying annual discount rates of time

20

Ikeda S and Kobayashi M: Economic evaluation of drug-eluting stents

Table 7 Results of Sensitivity Analysis Using Different Presumptions
on CABG Cost

seem that introduction of SES for stenting deserves tobe promoted actively, not only for clinical but also economic reasons.
While promoting the diffusion of economically dominant medical technology like SES and ensuring thestable supply of medical devices needed for such technology, we must consider not only the economic impact
for the society but also the management of medical
facilities, the cost of developing and manufacturing
medical materials, and the expenses borne by patients.
In the United States, it has been pointed out that the
reimbursement prices of drug-eluting stents (e.g., SES)
do not appropriately match the costs incurred for theirdevelopment and manufacture. For example, theamount paid under the DRG/PPS system for the use of
a drug-eluting stent in Medicare beneﬁciaries has been
set at a level only $1800 higher than the amount for
conventional stents per patient, and this amount does
not cover the extra cost needed for the manufacture ofthis new stent. This reimbursement fee policy may
make hospitals hesitant to use the drug-eluting stents.
Furthermore, it is expected that the introduction of
drug-eluting stents would reduce the number ofpatients requiring CABG or re-PTCA, leading to additional decreases in hospital revenues. These factors may
work against the use of drug-eluting stents. The William
Beaumont Hospital in Michigan, USA, has published
its estimate that hospital revenue will be decreased by$3.8 million if drug-eluting stents are used in 50% of
patients undergoing stenting.19 The Duke University
Medical Center, North Carolina, estimates that if drugeluting stents are used in 85% of all stent operations,the hospital will suffer a loss of $4.75 million in the ﬁrst
year and $5.6 million each year thereafter.20
In Europe, SES was launched in the market on April
15 2002. However, it has been pointed out that sincemost of the additional cost for SES stenting is borne by
the patients, SES has occupied just 12% or less of theentire stent market even 1 year after its launch.21
When viewed from the standpoint of Japanese hospitals, introduction of SES will reduce the hospital’s
proﬁts due to the inevitable decrease in the number ofpatients requiring re-PTCA or CABG. To facilitate
utilization of medical technology that has excellent
clinical efﬁcacy, and is expected to cut long-term medical expenditures, it is necessary to ensure appropriate
payment policies and measures to stimulate their use.
The results of the present economic analyses will be ofsome help in judging the appropriateness of the prices
set in individual cases.
This study has several important limitations. First,
the results of SIRIUS study may not be generalizable tothe full population of PCI patients. In particular, the
SIRIUS trial included a large percentage of complex
PCI lesions, including long lesions, smaller vessels, andexpected
medical cost

2-yearcumulativeﬁrst year second medical
year
cost

expected 3-year
medical cumulacost for tive
third
medicalyear
cost

assumed BMS ¥2,287,000 ¥49,000 ¥2,336,000 ¥41,000 ¥2,377,000
cost A patientSES¥2,118,000 ¥31,000 ¥2,149,000 ¥30,000 ¥2,179,000
patient
assumed BMS ¥2,280,000 ¥47,000 ¥2,326,000 ¥39,000 ¥2,366,000
cost B patientSES¥2,110,000 ¥29,000 ¥2,140,000 ¥28,000 ¥2,167,000
patient

Table 8 Results of Sensitivity Analysis Using Different Annual Discount Rates
expected
medical cost

expected
medicalcost for
third
year

3-yearcumulative
medicalcost

BMS¥2,324,000 ¥56,000 ¥2,380,000
patient
SES¥2,155,000 ¥39,000 ¥2,193,000
patient¥47,000¥2,427,000¥36,000¥2,230,000

3.5% BMS¥2,324,000 ¥56,000 ¥2,379,000
patient
SES¥2,155,000 ¥39,000 ¥2,193,000
patient¥47,000¥2,426,000¥36,000¥2,229,000

ﬁrst year3%

2-yearcumulative
second medical
year
cost

preference. Whether the annual discount rate was set
at 3% or 3.5%, the cost for the ﬁrst year, the 2-year
cumulative cost, and the 3-year cumulative cost were
smaller for the SES than for the BMS patient.
Discussion
The SES analyzed in the present study is a medical
device of higher cost as compared to the existing BMS.
The introduction and diffusion of the use of SES may
have non-ignorable effects on medical resources.
According to the present study, the introduction of the
SES is expected to signiﬁcantly reduce the incidence ofrestenosis and thus save medical costs. Therefore, fromthe standpoints of society and health insurers, it would

Keio J Med 2006; 55 (1): 15–22

diabetic patients. As a result, the observed clinicalrestenosis rate was relatively high compared with routine clinical practice.22
Second, our analysis was limited to a 3-year followup period. Although longer-term follow-up would havebeen enlightening, previous studies suggest that therestenosis process is largely complete after 12 months.23
Thus, it seems unlikely that the cost-effectiveness of
SES would be less favorable with longer follow-up.
Third, the present study did not take into account theoutpatient medication costs and follow-up costs. These
costs were considered to be similar except that patients
receiving SES stenting need to be treated with antithrombotic drugs for 3 months or longer.24 In Japan,
ticlopidine (Panaldine) has been authorized as anantithrombotic agent for use after PCI. The cost of thisdrug administered for 3 months at the dose level of 300
mg/day is ¥6,831. Therefore, even when the additional
cost of this drug is taken into account for the SES
patient, the economic dominance of SES remains
unchanged.
Finally, since no large-scale clinical trials of SES
have been conducted in Japan, it is an open question
whether or not the clinical results of the foreign SIRIUS study are applicable to Japan.
It would be too hasty to evaluate the appropriatenessof the price of SES in Japan at present. A careful review of whether or not the price set will induce inefﬁcient selection of treatment and become disadvantageous to patients would be necessary.
Conclusion
We estimated how the use of SES instead of theconventional BMS for PCI would affect the medical
costs over a period of 3 years in Japan, on the basis ofavailable published data. The use of SES is expected tosigniﬁcantly reduce the percentage of patients requiringrevascularization for restenosis, and thereby reduce thecumulative 3-year medical costs as compared to stenting using the BMS.
Acknowledgments: The authors wish to thank Professor Naoki
Ikegami for his valuable suggestions.

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