Dual antiplatelet therapy after drug-eluting stent implantation ⁎editorials published in the journal of the american college of cardiology reflect the views of the authors and do not necessarily represent the views of jacc or the american college of cardiology.
Journal of the American College of Cardiology
2012 by the American College of Cardiology Foundation
http://dx.doi.org/10.1016/j.jacc.2012.08.003
consistent lower rate of late or very late ST A recent
network meta-analysis presented the provocative findingthat within 2 years, EES might have a lower risk of ST than
BMS which, unlike common perception, might bebased on the possibility that polymeric coating could reduce
stent thrombogenicity This lower rate of ST withnewer-generation DES might be attributable to better
implantation technique, improved stent platform, thinnerstrut thickness, more biocompatible polymers, type and
amount of antiproliferative drug, or a combination thereof. Of note, in most contemporary DES trials, prolongedDAPT intake for at least 12 months was mandatory,
although the optimal duration of DAPT is still lacking
DAPT invariably increases the risk of major bleedings
The bleeding risk correlates with the duration ofDAPT and bleeding events clearly have a negative
Drug-eluting stents (DES) were introduced in interven-
impact on outcomes of patients after PCI This raises
tional practice more than 10 years ago and rapidly replaced
2 important questions, which are momentous for patients
bare-metal stents (BMS) for treatment of coronary artery
with a high likelihood for bleeding events, with the need for
disease because of their superior capability to reduce the
nondeferrable or unplanned noncardiac surgery or invasive
need for restenosis-driven repeat intervention. Soon, it
procedures, for elderly or fragile patients, and for patients
became obvious that besides optimal stenting technique,
with low drug adherence: First, are there certain conditions
dual antiplatelet therapy (DAPT), which means the com-
allowing us to safely shorten DAPT to Ͻ12 months after
bination of aspirin and a P2Y12 platelet receptor inhibitor,
DES implantation, and second, what are the consequences
has to be established for a prolonged time after stent
of DAPT discontinuation (temporary or permanent), in
implantation in order to avoid potentially catastrophic stent
thrombosis (ST). In the era of first-generation DES, it
In this issue of the Journal, Kim et al. address the
turned out that premature discontinuation of DAPT, which
first question. In the RESET (REal Safety and Efficacy of
means Ͻ3 months for sirolimus-eluting stents (SES) and
3-month dual antiplatelet Therapy following Endeavor
Ͻ6 months for paclitaxel-eluting stents (PES), is a strong
zotarolimus-eluting stent implantation) trial, 2,148 patients
predictor of ST and this relationship is more pronounced
with stable angina, unstable angina, or acute myocardial
in patients with acute coronary syndromes receiving DES
infarction (MI) undergoing elective PCI were enrolled, with
As additional safety concerns arose from reports of an increased
1,059 randomized to the Endeavor (Medtronic, Santa Rosa,
risk of late and very late (Ͼ1 year) ST events with first-
California) zotarolimus-eluting stent (E-ZES) and 3
generation DES an attitude towards “the longer, the
months of DAPT and 1,058 patients treated with standard
better” DAPT therapy developed. This is reflected in current
12-month DAPT and other DES (Resolute [Medtronic]
guidelines of the American societies recommending at least 12
zotarolimus-eluting stent [R-ZES], EES, or SES). Patients
months of DAPT with clopidogrel after DES implantation
with significant left main disease, in-stent restenotic lesions,
and the European Society of Cardiology endorsing 6 to 12
chronic total occlusions, or patients with acute ST-segment
months of DAPT treatment after DES implantation and 12
elevation MI (STEMI) were excluded from the trial. At 12
months for all patients after ACS, irrespective of revascular-
months, the combined endpoint of cardiovascular death,
ization strategy Meanwhile, second-generation DES with
MI, ST, target vessel revascularization (TVR), or bleeding
durable polymers such as everolimus-eluting stents (EES) or
occurred in 4.7% of patients in both treatment arms (p Ͻ
zotarolimus-eluting stents (ZES) and third-generation DES
0.001 for noninferiority). Overall, there was no significant
with biodegradable polymers and abluminal coating such as
difference in any of the individual components of the
biolimus-eluting stents (BES) widely replaced first-generation
primary endpoint. Definite or probable ST occurred in 2
DES because of improved stent deliverability while exhib-
patients (0.2%) treated with E-ZES, both within the first
iting equal or superior antiproliferative efficacy, and a
month. Three patients (0.3%) had ST in the conventional12 months DAPT therapy arm, all of them between 3 and12 months. There was no significant difference in the
*Editorials published in the Journal of the American College of Cardiology reflect theviews of the authors and do not necessarily represent the views of JACC or the
primary endpoint in any of the subgroups, including pa-
tients with diabetes mellitus and those with acute MI.
From the Department of Cardiology & Pulmonology, Charité–Campus Benjamin
Considering the RESET trial, is it now a safe strategy to
Franklin, Berlin, Germany. Dr. Witzenbichler has received lecture fees from AbbottVascular, Biotronik, Boston Scientific, and Medtronic.
implant E-ZES and limit DAPT to 3 months? Caution
Early Discontinuation of Dual Antiplatelet Therapy
should be advised in interpretation of the data. First, in their
nonadherence can be based on disruption because of bleed-
power calculations, the authors assumed a 10% incidence for
ing events or noncompliance, on the recommendation of
the primary endpoint at 12 months with a noninferiority
physicians (medical decision) who have felt that the patients
margin of 4%, where in fact the event rate was low with
no longer need this therapy (usually permanent), or on a
4.7%. Therefore, statistically, a much larger sample size
guided and recommended interruption because of a surgical
would have been needed to prove the hypothesis. Second,
or invasive procedure, usually temporary and not longer
the low event rate is unexpected and might in part be
than 14 days; it can be brief (Ͻ5 days), temporary or
explained by the anatomic low-risk profile as defined in the
permanent. The Spanish investigators prospectively col-
inclusion/exclusion criteria of the trial, which makes it
lected data on 1,622 all-comer patients undergoing implan-
difficult to translate the findings to a broader all-comer
tation of at least 1 DES. The major findings are as follows:
population. Third, the investigators choose the E-ZES
First, DAPT interruption for any reason was not infrequent
because of a supposedly better safety profile. The phospho-
and occurred in 10.6% of the patients, although in only 1
rylcholine polymer coating of the Endeavor stent accounts
patient, ATD was observed within the first 4 weeks.
for a rapid release of zotarolimus within 2 weeks, resulting
Second, in the majority of the patients with ATD, the
in a reduced antiproliferative effect, reflected by early neo-
interruption was temporary, and third, the composite end-
intimal growth and higher late loss, which did not translate
point of cardiac death or acute coronary syndrome occurred
in clinical events in patients with a low-risk profile but
in 5.4% of all patients, but only in a minority (8%) of those
became evident in a more daily-practice population
patients was ATD at any time before the event noted. In
The hypothesis that this E-ZES–typical feature of early
multivariate analysis, ATD was not found to be predictive
neointimal growth would be protective against late ST was
challenged by the SORT OUT III (Randomized Clinical
The authors have to be acknowledged for their thorough
Comparison of the Endeavor and the Cypher Coronary
assessment of ATD, as most trials and registries simply
Stents in Non-selected Angina Pectoris Patients) trial,
collect data of patients being “on” or “off” DAPT, ignoring
describing a 1.1% definite ST rate for E-ZES versus 0.3%
the dynamic nature of drug intake. The extent of ATD
for SES (p ϭ 0.048) at 12 months though the
within the first year was high; however, in their analysis,
incidence of very late ST (Ͼ12 months) was consistently
overall premature ATD seemingly did not translate into
low throughout the pivotal E-ZES trials Moreover,
serious consequences. This may be explained by the follow-
the follow-up time of 12 months in the RESET trial might
ing issues: First, in 65% of the cases, ADT was temporary
not be long enough to detect potential safety differences.
(median: 7 days), whereas it was shown that the median
Fourth, industry has already reacted and replaced the
interval from discontinuation of thienopyridine to ST was
E-ZES by its successor, the Resolute-ZES (R-ZES) with a
13.5 days for the first 6 months Second, the temporal
different slow-release polymer (BioLinx) and improved
association between ATD and consecutive events beyond 6
antiproliferative activity. Therefore, in most catheterization
months is known to be lenient and twice as many
laboratories, the E-ZES has disappeared from the shelves
patients in this study disrupted their DAPT at 6 to 12
and is replaced by the R-ZES. Fifth, in the control arm, a
months. Third, because the event rates were low, the power
mixture of first-generation (SES) and second-generation
of the study is limited and the confidence intervals are wide.
DES (EES, R-ZES) was used instead of the E-ZES,
Fourth, the authors were well advised to do simulations of
hindering direct comparisons, and finally, 14% of the
ATD in those patients who died of cardiac reasons. If in
population in the trial presented with non–STEMI, the
18.8% of these cases DAPT had been interrupted before
patient group probably having the most benefit from pro-
death, the association between ATD and cardiac events
longed DAPT by preventing future atherothrombotic
would have been significant. As it is difficult to receive
events regardless of the stent type implanted. The OPTI-
detailed information from relatives on DAPT adherence of
MIZE (Optimized Duration of Clopidogrel Therapy Fol-
the deceased person, an even higher misclassification is quite
lowing Treatment With the Endeavor Zotarolimus-Eluting
conceivable. For these reasons, the data can only suggest
Stent in the Real World Clinical Practice) trial
that a brief interruption of DAPT does not have a large
currently randomizing 3,120 patients to 3
impact on ischemic risk. For more information on different
versus 12 months of DAPT after E-ZES implantation, will
modes of nonadherence to DAPT, subsequent outcomes,
probably give us a more robust insight into the safety of this
and their relation to nonadherence, we have to await the
approach, although the results cannot guide catheterization
results of the observational PARIS (Patterns of Non-
laboratories that have already abandoned the E-ZES.
Adherence to Dual Anti-Platelet Regimen In Stented
The work of Ferreira-Gonza´les et al. in this issue of
Patients) trial following more than 5,000
the Journal engages with the topic of antiplatelet therapy
patients after stent placement over 2 years.
discontinuation (ATD) during the first 12 months. They
Are these 2 reports now suggesting that the time has
have extended their previous work on incidence and predic-
come to slacken the reins in antiplatelet therapy after DES?
tors of ATD in the same population, to the consecutive
With newer-generation DES, 6 months DAPT might be
risk for cardiac death and MI associated with it. DAPT
sufficient, and 3 months not completely of the wall in
Early Discontinuation of Dual Antiplatelet Therapy
low-risk groups. Brief interruption of DAPT beyond 4
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weeks might not be associated with a dramatic risk increase.
genicity early in high-risk interventional settings is driven by stentdesign and deployment and protected by polymer-drug coatings.
However, the patient- and device-related criteria safely
allowing early DAPT withdrawal or interruption still have
12. Yusuf S, Zhao F, Mehta SR, Chrolavicius S, Tognoni G, Fox KK.
to be determined. Until then, we should be cautious and do
Effects of clopidogrel in addition to aspirin in patients with acutecoronary syndromes without ST-segment elevation. N Engl J Med
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CABG Registry Cohort-2 Investigators. Duration of dual antiplatelet
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bichler, Department of Cardiology & Pulmonology, Charité–
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Smoking Tutor’s Notes Edith Okola with Holly Halstead Ann Wylie These resources are freely available to be copied and used for teaching and public health studies. Please acknowledge author and LTPHN for publication. SMOKING Why is smoking important? Approximately 10 million ad
„Österreichische Richtlinie für das Toxoplasmose-Screening in der Schwangerschaft und frühen Kindheit“ Screening, Therapie und kindliches Follow-up Diese Richtlinie wurde unter der Koordination von Andrea-Romana Prusa unter Mitarbeit der „Arbeitsgruppe Toxoplasmose“ im Rahmen der Arbeitsgruppe Infektiologie der Österreichischen Gesellschaft für Kinderheilkunde