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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 26, No 4, July/August 2015
AFRICA
e19
Bare-metal stent thrombosis two decades after stenting
Aynur Acibuca, Demet Menekse Gerede, Veysel Kutay Vurgun
Abstract
Very late bare-metal stent (BMS) thrombosis is unusual in
clinical practice. To the best of our knowledge, the latest that
the thrombosis of a BMS has been reported is 14 years after
implantation. Here, we describe a case of BMS thrombosis
that occurred two decades after stenting. A 68-year-old male
patient was admitted with acute anterior myocardial infarc-
tion. This patient had a history of BMS implantation in
the left anterior descending coronary artery (LAD) 20 years
previously. Immediate coronary angiography demonstrated
acute thrombotic occlusion of the stent in the LAD. With this
case, we are recording the latest reported incidence of BMS
thrombosis after implantation.
Keywords:
bare-metal stent, very late stent thrombosis, acute
coronary syndrome, antiplatelet therapy
Submitted 7/1/15, accepted 25/3/15
Cardiovasc J Afr
2015;
26
: e19–e21
www.cvja.co.zaDOI: 10.5830/CVJA-2015-034
Stent thrombosis is a rare but serious complication that can lead
to death or myocardial infarction (MI). Premature cessation of
dual antiplatelet therapy is the most important risk factor.
Stent thrombosis is classified according to the ARC (academic
research consortium) criteria as definite, probable or possible.
1
Stent thrombosis can occur acutely (within 24 hours), sub-acutely
(within 30 days), or as late as one year (late) or more (very late)
after stent placement.
Both randomised trials and observational study data have
demonstrated that the cumulative rate of stent thrombosis is
similar for bare-metal and first-generation drug-eluting stents
for up to five years.
2,3
There may be a slight predominance of
bare-metal stent (BMS) thrombosis between 30 days and one
year, with a slight preponderance of drug-eluting stent (DES)
thrombosis beyond one year.
4
Here, we report a case of very late BMS thrombosis that
presented as anterior myocardial infarction 20 years after stent
implantation for left anterior descending coronary artery (LAD)
disease.
Case report
A 68-year-old non-diabetic, normotensive, ex-smoking male
patient was admitted to our coronary care unit complaining
of chest pain of one hour onset, which was unresponsive to
nitroglycerin. This patient’s history included a bare-metal stent
implantation for a proximal LAD lesion 20 years previously.
He had been discharged on acetyl salicylic acid; however, one
month later, he discontinued antiplatelet medication and stopped
attending his control visits.
The electrocardiogram showed acute anterior myocardial
infarction (Fig. 1), and an immediate coronary angiography
showed total occlusion of the implanted stent in the proximal
LAD (Figs 2A, B). Balloon angioplasty was therefore performed
(Alvimedica balloon, 3 × 15 mm). TIMI 3 (thrombolysis in
myocardial infarction) coronary flow was achieved (Fig. 2C);
however, there appeared to be a need to perform percutaneous
transluminal coronary angioplasty
(PTCA) for the diagonal
coronary
artery branch (Advancer Hp balloon, 2 × 15 mm).
Plaques were found on the right and circumflex coronary arteries.
Following the administration of a bolus, tirofiban infusion was
initiated post-procedurally and was continued for 24 hours.
During the follow-up period, ST-segment resolution was
achieved. Transthoracic echocardiography showed modest
impairment of the left ventricular systolic function with a global
ejection fraction of 52%. On the sixth day after admission, this
patient was discharged on dual antiplatelet therapy.
Discussion
While very late stent thrombosis may be expected with the use of
DES, it is rare with the use of BMS. A large, retrospective study
reported that the cumulative incidence of stent thrombosis after
BMS implantation was 1.3% at five years, and 2.0% at 10 years.
5
The expected risk factors related to very late stent thrombosis
are delayed neo-intimal proliferation and ongoing vessel
inflammation.
6
This is unexpected for BMS because stent
endothelialisation is considered to be complete four weeks after
the intervention. There are some case reports in the literature
of very late thrombosis of BMS presenting with acute coronary
syndrome occurring up to 14 years after implantation.
7-9
However,
many of them have no established cause.
8,9
We believe this case of acute MI was caused by very late
stent thrombosis, for a number of reasons. First, the patient
was asymptomatic until this point; he had no angina or angina-
equivalent symptoms. Second, a guide wire was easily passed
through the occluded stent. Finally, balloon angioplasty was
enough to obtain TIMI 3 coronary flow; there was no need for
stent re-implantation.
The pathophysiology of very late BMS thrombosis is
Department of Cardiology, Ankara University School of
Medicine, Ankara, Turkey
Aynur Acibuca, MD,
aynuracibuca85@gmail.comDemet Menekse Gerede, MD
Veysel Kutay Vurgun, MD
Case Report