Drug-Eluting Coronary Artery Stents
GREGORY?J.?DEHMER,?MD,?and?KYLE?J.?SMITH,?MD,?Scott & White Healthcare, Temple, Texas
cedure,? dramatically? improved? safety,? and?
ince? the? first? balloon? angioplasty,?
the? use? of? percutaneous? coronary?
intervention? has? grown? substan-
tially.? Advances? in? this? technique?
Balloon Angioplasty and Stenting
A? major? limitation? of? balloon? angioplasty?
is? lesion? restenosis,? which? occurs? in? up? to? ?
deflation? and? removal? of? the? balloon,? the?
progressive? constriction? (restenosis)? of? the?
artery? dissections,? markedly? reducing? the?
Although? bare-metal? stents? effectively?
address? two? of? the? mechanisms? leading?
to? restenosis? (i.e.,? elastic? recoil? and? vessel?
constriction? during? healing),? they? do? not?
plasia.? Rather,? they? cause? an? exaggerated?
Many advances have been made in the percutaneous treatment of coronary artery disease during the past 30 years.
Although balloon angioplasty alone is still performed, the use of coronary artery stents is much more common.
Approximately 40 percent of patients treated with balloon angioplasty developed restenosis, and this was reduced to
roughly 30 percent with the use of bare-metal stents. However, restenosis within the stent can occur and is difficult
to treat. Drug-eluting stents were developed to lower the rate of restenosis, which now occurs in less than 10 percent
of patients treated with these stents. There have been concerns about abrupt thrombosis within drug-eluting stents
occurring late after their implantation, leading to acute myocardial infarction and death. Recent studies have allevi-
ated, but not completely dispelled, these concerns. Strict adherence to dual antiplatelet therapy with aspirin and a
thienopyridine is required after stent placement, and the premature discontinuation of therapy is the most important
risk factor for acute stent thrombosis. Adequate communication between cardiologists and primary care physicians
is essential not only to avoid the premature discontinuation of therapy, but also to identify, before stent placement,
those patients in whom prolonged antiplatelet therapy may be ill-advised. Elective surgery following stent placement
should be delayed until the recommended course of dual antiplatelet therapy has been completed. (Am Fam Physician.
2009;80(11):1245-1251, 1252-1253. Copyright © 2009 American Academy of Family Physicians.)
▲ Patient information:
A handout on coronary
artery disease and the use
of stents, written by the
authors of this article, is
provided on page 1252.
Table 1. Success and Complication Rates of Balloon
Angioplasty and Stenting
Type of intervention
1 to 2.5
1.9 to 5.8
< 0.3 to 0.6
< 0.3 to 0.6< 10
note: The restenosis rates shown are based on repeat angiography performed six to
nine months after the initial procedure. Roughly one half of these patients are symp-
tomatic and require another procedure.
CABG = coronary artery bypass graft.
Information from references 2 through 4.
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1246 American Family Physician
Volume 80, Number 11 ◆ December 1, 2009
after? stent? placement? compared? with? balloon? angio-
Drug-eluting? stents? are? coated? with? a? drug? delivery?
eluting? stents? have? further? reduced? the? occurrence? of?
Choosing a Stent
ment.? Two? main? factors? are? considered? when? choos-
provide? better? long-term? outcomes? than? bare-metal?
infarction? (MI),11? in-stent? restenosis? of? a? bare-metal?
SORT: KEY RECOMMENDATIONS FOR PRACTICE
the recommended dosages for dual antiplatelet therapy are 162 to 325 mg of aspirin daily and
75 mg of clopidogrel (Plavix) or 10 mg of prasugrel (effient) daily, but ticlopidine (formerly
ticlid) in a dosage of 250 mg twice daily may be used if the patient cannot tolerate clopidogrel
the preferred duration of dual antiplatelet therapy after bare-metal or drug-eluting stent
placement is one year.
the minimum recommended duration of dual antiplatelet therapy after stent placement is
one month for bare-metal stents, three months for the sirolimus (Rapamune)-eluting stent
(Cypher), and six months for other drug-eluting stents. In special circumstances, two weeks of
therapy after bare-metal stent placement may be considered.
Patients at increased risk of gastrointestinal bleeding should receive acid suppression therapy
while receiving dual antiplatelet therapy. Proton pump inhibitors may interfere with clopidogrel
metabolism, but data are conflicting so an H2-receptor blocker or antacids may be preferable.
After the recommended duration of treatment with dual antiplatelet therapy, aspirin (75 to
162 mg daily) should be continued indefinitely.
Following stent placement, elective surgery should be delayed until the recommended course of
dual antiplatelet therapy is completed. If surgery cannot be delayed, it should be performed
while the patient is on dual antiplatelet therapy. If that is not feasible, the thienopyridine
should be stopped for the shortest time possible and then restarted.
C 14, 19, 30, 31
C19, 30, 31
C11, 14, 19, 30,
C 19, 32, 39
A = consistent, good-quality patient-oriented evidence; B = inconsistent or limited-quality patient-oriented evidence; C = consensus, disease-
oriented evidence, usual practice, expert opinion, or case series. For information about the SORT evidence rating system, go to http://www.aafp.
Figure 1. Left anterior oblique view of a coronary angio-
gram showing the right coronary artery. In the mid-vessel,
there is a severe narrowing within a previous bare-metal
stent. The stent is visible within the wall of the artery as
two fine black lines parallel to the artery at the site of the
December 1, 2009 ◆ Volume 80, Number 11?
American Family Physician 1247
risk? of? bleeding,? or? those? who? are? known? to? need? ?
the? duration? of? dual? antiplatelet? therapy? is? shorter.? ?
surgical? revascularization? or? further? increasing? the?
of? early? stent? thrombosis.14?A? new? antiplatelet? agent,?
in? 4.9? percent? of? patients? with? drug-eluting? stents,?
the? United? Kingdom? to? remove? them? from? use? alto-
angina? that? often? required? another? revascularization?
Causes of Stent Thrombosis
stent? is? eventually? covered? by? healthy? endothelium.?
which? can? stimulate? late? thrombus? formation? after?
sons? not? completely? understood,? a? small? number? of?
cell? death? (apoptosis)? in? the? artery? wall? behind? the?
On-Label vs. Off-Label Use
Table 2. Types of Drug-Eluting Stents Available
for Clinical Use
nameMetal platformDrug used
CypherStainless steel Sirolimus
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Volume 80, Number 11 ◆ December 1, 2009
Figure 2. Sequence of left anterior oblique coronary angiograms of the right coronary artery, showing late stent throm-
bosis. In February 2007, (A) severe and diffuse arterial disease was apparent (between arrows), (B) with immediate
results after placement of three overlapping drug-eluting stents. In January 2009, (C) the patient presented with acute
inferior myocardial infarction and had stent thrombosis. The occluded artery (black arrow) and faint shadow of stents
beyond the occlusion (white arrows) are visible. (D) Angiogram of the right coronary artery after treatment of the
stent thrombosis with a combination of balloon angioplasty, thrombus aspiration, and additional stent placement.
December 1, 2009 ◆ Volume 80, Number 11?
American Family Physician 1249
lesion? characteristics? studied? in? the? initial? trials? (“on-
Postprocedural Medical Therapy
and? a? thienopyridine? derivative? is? imperative.14,19,30,31?
side? effects,? but? ticlopidine,? 250? mg? twice? daily,? may?
When? drug-eluting? stents? were? initially? released?
for? clinical? use,? the? duration? of? antiplatelet? therapy?
platelet? therapy? following? stent? placement? is? optimal,?
sirolimus? (Rapamune)-eluting? stents,? and? six? months?
In? those? at? increased? risk? of? gastrointestinal? bleed-
Table 3. AHA/ACC/SCAI/ACS/ADA Science Advisory Recommendations to Eliminate Premature
Discontinuation of Thienopyridine Therapy (Clopidogrel [Plavix] or Ticlopidine [Formerly Ticlid])
1. Before stent implantation, the physician should discuss the necessity of dual antiplatelet therapy. In patients not expected to
comply with 12 months of thienopyridine therapy, for economic or other reasons, strong consideration should be given to
avoiding a drug-eluting stent.
2. In patients preparing for percutaneous coronary intervention who are likely to require invasive or surgical procedures within
the next 12 months, consideration should be given to use of a bare-metal stent or balloon angioplasty with provisional stent
implantation instead of the routine use of a drug-eluting stent.
3. A greater effort by health care professionals must be made before patient discharge to ensure that patients are properly and
thoroughly educated about the reasons for which they are prescribed thienopyridines and the significant risks associated with
prematurely discontinuing such therapy.
4. Patients should be specifically instructed before hospital discharge to contact their treating cardiologist before stopping any
antiplatelet therapy, even if told to stop such therapy by another health care professional.
5. Health care professionals who perform invasive or surgical procedures and are concerned about peri- and postprocedural
bleeding must be made aware of the potentially catastrophic risks of premature discontinuation of thienopyridine therapy.
these professionals should contact the patient’s cardiologist if issues about the patient’s antiplatelet therapy are unclear, to
discuss optimal patient management strategy.
6. elective procedures for which there is significant risk of peri- or postoperative bleeding should be deferred until patients have
completed an appropriate course of thienopyridine therapy (12 months after drug-eluting stent implantation if they are not at
high risk of bleeding, and a minimum of one month for bare-metal stent implantation).
7. For patients with drug-eluting stents who will have subsequent procedures that mandate discontinuation of thienopyridine
therapy, aspirin should be continued if at all possible and the thienopyridine restarted as soon as possible after the procedure
because of concerns about late stent thrombosis.
8. the health care industry, insurers, the U.S. Congress, and the pharmaceutical industry should ensure that issues such as drug
cost do not cause patients to prematurely discontinue thienopyridine therapy, which could cause catastrophic cardiovascular
ACC = American College of Cardiology; ACS = American College of Surgeons; ADA = American Dental Association; AHA = American Heart Associa-
tion; SCAI = Society for Cardiovascular Angiography and Interventions.
Adapted from Grines CL, Bonow RO, Casey DE Jr., et al. Prevention of premature discontinuation of dual antiplatelet therapy in patients with coro-
nary artery stents: a science advisory from the American Heart Association, American College of Cardiology, Society for Cardiovascular Angiography
and Interventions, American College of Surgeons, and American Dental Association, with representation from the American College of Physicians.