Medtronic Study Confirms Long-Term Safety of Drug-Eluting Coronary Stents
Largest Prospective Randomized Drug-Eluting Stent Trial Ever Presented, ESC Late-Breaker on PROTECT Reveals Low Rates of Stent Thrombosis Through Three Years of Follow-Up
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Endeavor and Cypher Drug-Eluting Stents |
August 27, 2012 -- Minneapolis and Munich --
Results of a landmark clinical
trial, PROTECT, presented for the first time today at the 2012 European Society of
Cardiology (ESC) Congress, confirm the long-term safety of drug-eluting stents in the
treatment of coronary artery disease in real-world clinical practice.
Dr. William Wijns, one of the study's co-principal investigators, presented the findings
at ESC 2012 as part of a late-breaking clinical trials session. The results of PROTECT
the largest prospective randomized drug-eluting stent trial ever presented and powered
for stent thrombosis - were simultaneously published by The Lancet. The study was
sponsored by Medtronic, Inc. (NYSE: MDT).
Involving more than 8,700 patients at 196 centers in 36 countries across five continents,
PROTECT was initiated to study the occurrence of a rare but serious adverse event
known as stent thrombosis the formation of a blood clot inside the stent, which
serves as a scaffold to keep the artery open. Stent thrombosis is often associated with
serious clinical events, such as cardiac death and myocardial infarction (heart attack).
PROTECT (n=8,709) randomly assigned study patients to receive the Endeavorฎ
zotarolimus-eluting stent from Medtronic or the Cypherฎ sirolimus-eluting stent from
Johnson & Johnson in equal numbers. On the primary endpoint, the trial showed very
low rates of definite/probable stent thrombosis with no statistically significant
difference in cumulative rates through three years of follow-up: 1.42 percent for
Endeavor; 1.79 percent for Cypher (p=0.224). However, stent thrombosis rates after one
year, known as very late stent thrombosis, were significantly lower with Endeavor (0.3
percent) compared to Cypher (1.1 percent, p<0.001).
"Based on its excellent clinical outcomes and low rates of stent thrombosis through
three years of follow-up, PROTECT confirms the long-term safety of percutaneous
coronary intervention with these drug-eluting stents," said Dr. Wijns, an interventional
cardiology and co-director of the Cardiovascular Center in Aalst, Belgium. "The decline
in stent thrombosis rates since the initial concern emerged at ECS 2006 cannot be
denied. This likely results from a combination of factors: improvements in patient
selection and procedural techniques, and duration and/or compliance with dual
antiplatelet therapy."
Dual antiplatelet therapy usage in PROTECT followed current ESC and AHA/ACC/
SCAI guidelines, with 88 percent of patients remaining on dual antiplatelet therapy at
one year and 30 percent of patients at three years.
As with stent thrombosis, the study's secondary endpoints resulted in low, comparable
rates of death and large, non-fatal myocardial infarction through three years of patient
follow-up: 5.3 percent for Endeavor; 6.0 percent for Cypher (p=0.16). Also of note were
the low rates of target vessel revascularization at three years: 8.2 percent for Endeavor;
7.1 percent for Cypher (p=0.03).
While drug-eluting stents have been shown to significantly reduce restenosis (the
renarrowing of the treated arterial segment) compared to bare-metal stents, post-hoc
and pooled analyses at ESC 2006 indicated potential differences in stent thrombosis
rates between bare-metal stents and drug-eluting stents. These analyses caused concern
of very late stent thrombosis with drug-eluting stents.
In 2007 the U.S. Food and Drug Administration (FDA) recommended that larger and
longer studies be conducted to assess the risk of infrequent events, such as stent
thrombosis. The FDA also recommended focusing on important safety end points
(death and heart attack) and on the appropriate duration of dual antiplatelet therapy.
PROTECT was funded by Medtronic to help address these issues. Several large meta-analyses have been conducted to better understand the rates of stent thrombosis with
drug-eluting stents. However, due to their individual limitations, study designs and
retrospective nature, they are ultimately insufficient to show with statistical certainty a
difference in low frequency events. These factors often make their results hypothesis-generating rather than definitively conclusive.
PROTECT is the largest prospective randomized drug-eluting stent trial ever presented
and powered for stent thrombosis.
In collaboration with leading clinicians, researchers and scientists worldwide,
Medtronic offers the broadest range of innovative medical technology for the
interventional and surgical treatment of cardiovascular disease and cardiac
arrhythmias. The company strives to offer products and services that deliver clinical
and economic value to healthcare consumers and providers around the world.
About Medtronic
Medtronic, Inc. (www.medtronic.com), headquartered in Minneapolis, is the global
leader in medical technology alleviating pain, restoring health and extending life for
millions of people around the world.
Any forward-looking statements are subject to risks and uncertainties such as those
described in Medtronic's periodic reports on file with the Securities and Exchange
Commission. Actual results may differ materially from anticipated results.
Source: Medtronic,
Inc.
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