CLINICAL
NEWS
American College of Cardiology Extended Learning
ACCEL interviews and topical summaries of cardiology’s
most interesting research areas
For Which Patients (if Any) Should BMS be Considered?
Evidence and common sense
D
rug-eluting stents (DES) have dramatically
reduced the risk of restenosis and target
vessel revascularization (TVR) compared
with bare-metal stents (BMS). At first, there
seemed to be a cost to this beneficial effect: early
on, it appeared these new stents were associated
with an increased risk of late stent thrombosis.
Consequently, a second generation of DES sought to
improve safety, efficacy, and device performance.
That first-generation DES technology was significantly better than BMS, but the advantage was
limited. When investigators analyzed 15 randomized controlled trials (RCTs) comparing DES and
BMS in 7,843 ST-elevation myocardial infarction
(STEMI) patients, there were trends favoring DES
but no significant effect on all-cause death, cardiac
death, or MI.1 There was a trend in risk of definite
stent thrombus favoring BMS. TVR was the only
beneficial effect associated with DES (8.7% vs.
15.4% with BMS; p < 0.001), leading some to the
conclusion that there was a disconnect between
safety and efficacy related to DES use.
This led to the idea that a BMS is a good choice
in specific patients, such as individuals who may
not tolerate a long-term course of dual antiplatelet
therapy (DAPT).
Now, several clinical studies have demonstrated
that second-generation DES are demonstrably
better than earlier DES and associated with more
favorable outcomes. For example, Valgimigli et al.
conducted a patient-level meta-analysis evaluating
the effects of cobalt-chromium everolimus-eluting
stents (Co-Cr EES) versus BMS on fatal and nonfatal events over a median of 720 days.2 The data
came from five RCTs comprising 4,896 participants. Compared to BMS, this time DES use was
associated with clinically significant reductions in a
number of endpoints, with the one exception being
total mortality (Table). Although not included in
the table, fatal MI was more than 80% lower in the
Co-Cr EES group (0.08% vs. 0.8% in the BMS group;
adjusted hazard ratio [HR]: 0.11; 95% confidence
interval [CI]: 0.03 to 0.49; p = 0.004).
So, in contrast to first-generation stents, Co-Cr
EES implantation was associated with a reduction
in cardiac mortality, driven by significant reductions in major clinical endpoints.
In the paper, published in late 2014, the authors
concluded, “Our analysis challenges the current belief
that bare-metal stents are safer than drug-eluting stents.
Stent safety and efficacy can no longer be disconnected,
at least for some newer generation devices.”2
A recent study suggests why second-generation
DES are superior. A team of investigators in Japan
22
CardioSource WorldNews: Interventions
have a paper online before print
offering what they
think is the first
comprehensive
comparison of
chronic angioscopic findings
after BMS and
first- and secondgeneration DES.³
Coronary angioscopy revealed
more homogeneous coverage
with white neointima and less
thrombus after
second-generation
DES implantation
compared to firstgeneration DES.
Besides similar efficacy for both DES, the secondgeneration DES had a safety profile comparable to
that of BMS. The authors think their results may
explain the favorable clinical outcomes observed for
patients treated with second-gen DES.
ZEUS WEIGHS IN
Current guidelines suggest that one place for BMS
use today is in patients who might not be able to
adhere to long-term DAPT following DES placement.
Marco Valgimigli, MD, and his colleagues have also
looked at this specific issue.
Dr. Valgimigli was a multinational, randomized,
single-blinded study conducted at 20 sites in four
European countries.4 It was designed to evaluate the
combined efficacy and safety of a zotarolimus-eluting
stent (ZES) compared with BMS in uncertain DES
candidates.
In this case, that meant patients at high bleeding
risk (e.g., need for oral anticoagulation, previous
Meta-Analysis of Cobalt-Chromium Everolimus-Eluting Stents or BMS on
Events at 2 Years
TABLE
Hazard Ratio
(95% CI)
DES*
BMS
p Value
All-cause death
4.9%
5.9%
0.83
(0.65 to 1.06)
0.14
Cardiac mortality
2.7%
4.0%
0.67
(0.49 to 0.91)
0.01
Myocardial infarction (fatal and nonfatal)
4.0%
5.6%
0.71
(0.55 to 0.92)
0.01
Definite stent thrombosis
0.6%
1.4%
0.41
(0.22 to 0.76)
0.005
Definite or probable stent thrombosis
1.3%
2.6%
0.48
(0.31 to 0.73)
0.001
Target vessel revascularization
4.3%
10.2%
0.29
(0.20 to 0.41)
<0.001
*Cobalt-chromium everolimus-eluting stents
BMS = bare-metal stents; CI = confidence interval; DES = drug-eluting stents
September/October 2016