Biomedical Engineering Reference
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was 1.32. It was concluded that DES were associated with an increased rate of death,
as compared with BMS. This trend appeared after 6 months, when the risk of death
was 0.5 percentage point higher and a composite of death or myocardial infarction
was 0.5-1.0 percentage point higher per year. The long-term safety of DES needs to
be ascertained in large, randomized trials.
Diabetes mellitus is a major risk factor for restenosis in patients undergoing
percutaneous coronary intervention. Randomized controlled trials comparing DES
with BMS showed a marked decrease in in-stent restenosis and target lesion revas-
cularization with DES in the total patient population enrolled in the studies, includ-
ing patients with diabetes. Review of clinical trials comparing DES with BMS in
patients with diabetes shows that DES use is associated with a marked decrease in
in-stent restenosis and target lesion revascularization (Boyden et al.
2007
). The
analysis supports the current widespread use of DES in these high-risk patients.
Most of the DES studies have been done in coronary arteries. Internal mammary
arteries (IMAs) and veins are also used for revascularization of the myocardium in
myocardial ischemia. One study examined the safety and efficacy of DES for the
treatment of lesions in the IMA conduits and compared the outcomes with those
from BMS (Buch et al. 2006). DES implantation into IMAs appears safe and is
associated with low rates of recurrences. These results may support expansion of
use of DES for the management of IMA stenotic lesions.
A study at the Wake Forest University School of Medicine (Winston-Salem, NC)
investigated the outcome of BMS placed in 1,164 consecutive patients in the year
before the introduction of DES, which were subsequently placed in 1,285 consecu-
tive comparable patients (Applegate et al.
2007
). At 9 months, target vessel revas-
cularization and death were lower in the DES group than in the BMS group.
In conclusion, in this single-center observational study, use of DES in consecutive
unselected patients, most of whom would not have been eligible for inclusion in the
randomized trials of DES versus BMS, was associated with lower acute myocardial
infarction and death rates than in a comparable group of patients treated with BMS
in mid-term (9-month) follow-up. In another study the widespread adoption of DES
into routine practice was associated with a decline in the need for repeat revascu-
larization procedures and had similar 2-year risks for death or ST-elevation myo-
cardial infarction to bare-metal stents (Malenka et al.
2008
). With the current data
DES might still have an advantage over BMS in the treatment of myocardial infarc-
tion with ST-segment elevation with the vastly improved target vessel revascular-
ization rate by continuing long-term dual antiplatelet therapy, which has been
shown to be safe and effective in these patients (Yeter et al.
2009
). In patients with
ST-segment elevation myocardial infarction who were undergoing primary percu-
taneous coronary intervention, implantation of paclitaxel-eluting stents, as com-
pared BMS, significantly reduced angiographic evidence of restenosis or recurrent
ischemia necessitating repeat revascularization procedures and no safety concerns
were apparent at 1 year (Stone et al.
2009
).
In a large study conducted at Harvard Medical School on patients presenting
with acute myocardial infarction, treatment with DES was associated with decreased
2-year mortality rates and a reduction in the need for repeat revascularization
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