CLINICAL
NEWS JOURNAL COMMENTARY
Is There Any Reason to Keep
Bare-metal Stents on the
Shelf?
T
here is little controversy about the fact that
bare-metal stents (BMS) simply do not
compare to drug eluting stents (DES). Despite
the higher restenosis rates in BMS, there was concern
that delayed endothelialization of DES might lead to
late stent thrombosis with subsequent ischemic events
such as myocardial infarction of death. However, a
host of comparative studies have now shown that
shorter and shorter lengths of dual anti-platelet
therapy (DAPT) after stenting make no difference in
MACE outcomes between the use of BMS or DES.
The recent 2016 ACC/AHA Guideline Focused
Update on Duration of DAPT in Patients with Coronary Artery Disease emphasized (among others) the
following points:
1. Prolonged DAPT produces an inherent trade-off
between apparent increased ischemic risk from
restenosis/stent thrombosis and an increase in
bleeding risk due to DAPT.
2. Shorter duration DAPT therapy can be considered for patients with lower ischemic risk and
increased bleeding risk. Longer duration DAPT
therapy should be considered for patients with
higher ischemic risk and lower bleeding risk.
3. After BMS implantation, DAPT should be given
for a minimum of one month and in patients
with DES, DAPT should be continued for at least
6 months.
The updated guidelines point out that prior recommendations for DAPT therapy were based on the results of clinical trials using first generation DES stents
(now hardly used in clinical practice). The updated
guidelines are based on trials using newer generation
DES, which are safer and have a lower risk of stent
thrombosis due mainly to changes in design and polymer coatings. But for patients at high risk for bleeding
the guidelines are less forceful. A II-b recommendation states that in patients after DES impla ntation
ACC.org/CSWNInterventions
who develop a high risk of severe bleeding, discontinuation of clopidogrel after 3 months may be reasonable.
In fact, many of us continue to choose BMS for exactly such patients, assuming that the need for DAPT
is less stringent, and possibly DAPT can be discontinued as early as one month after BMS implantation. Is
this a good strategy?
Compared to BMS
patients, DES patients
had a lower (22.6%
vs. 29%) MACE, driven
by lower myocardial
infarction and target
vessel revascularization.
In the March 14 edition of JACC: Cardiovascular Interventions, Ariotti and colleagues report on a
pre-specified analysis from the ZEUS trial1 that may
help change our thinking. Within the ZEUS trial 828
patients fulfilled pre-defined criteria for high bleeding
risk (advanced age, indication for oral anticoagulants
or other pro-hemorrhagic medications, history of
recent bleeding requiring hospitalization or medical
attention, need for long term steroids or NSAIDS, and
even anemia). They received either a zotarolimus-eluting Endeavor Sprint Stent or a BMS and were given
a protocol-mandated 30 day DAPT regimen. Hard
MACE endpoints (death, myocardial infarction, target
vessel revascularization) were collected at 12 months.
As no surprise, in the substudy, patients with one
or more high bleeding risk criteria had worse outcomes owing to more ischemic and bleeding risks.
However, compared to BMS patients, DES patients
had a lower (22.6% vs. 29%) MACE, driven by lower
myocardial infarction and target vessel revascularization. In addition the composite of definite or probable
stent thrombosis was reduced in the DES patients.
There were no differences in bleeding complications
in the two groups. The authors’ conclusions, also
not surprisingly, are that patients with high bleeding
risk had a higher incidence of bleeding than patients
without bleeding risk. The risk was proportionally
greater depending in the number of high risk bleeding
criteria. But more importantly, in patients with stable
or unstable coronary disease, DES provided superior
efficacy and safety than BMS. These results were
consistent on further analyses that looked at two or
more high bleeding risk features or looking at each
bleeding risk criterion separately. Finally, patients with
BMS actually had longer duration of DAPT therapy
than DES patients because of the higher target vessel
revascularization rate due to more in-stent stenosis
or stent thrombosis in the in the BMS group (which
required further DAPT therapy).
There are few data in the literature to which the
ZEUS trial can be compared though many trials have
compared DES and BMS. The recently completed
DAPT trial2 excluded patients at high bleeding risk
and the study was not designed to compare DES
and BMS in high bleeding risk patients. The WOEST
trial3 asked a slightly different question than the
ZEUS trial—comparing patients needing oral anticoagulation who were given either clopidogrel alone or
colopidogrel plus aspirin for one month after BMS
Continued on page 31
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