New Canadian study finds drug coated heart stents to be safe:



    'Effective in High Risk Angioplasty Patients'

    TORONTO, Oct. 3 /CNW/ - Much controversy has developed over the past year
about the safety and potential complications of drug-eluting heart stents,
increasing the risk of possible fatal blood clots, even years after an
angioplasty procedure. However, a new Canadian study led by investigators from
Ontario's Institute for Clinical Evaluative Sciences (ICES) and McMaster
University's Program for Assessment of Technologies in Health, tells a
different story.
    Drug-eluting stents were found to be most effective in reducing the need
for repeat angioplasty procedures or bypass surgery in angioplasty patients at
the 'highest risk' for a renarrowing of the artery around the stent, without
significantly increasing the rate of death or risk of heart attack. Lead
Author, ICES Sr. Scientist, Dr. Jack Tu says, "This is good news, reassuring
patients and cardiologists about the safety of drug-eluting stents when used
in appropriate individuals. Our results also suggest physicians should be
selective in using drug-eluting stents, offering them to angioplasty patients
who are at the highest risk for repeat cardiac procedures."
    Reporting in the October 4th issue of the prestigious New England Journal
of Medicine, the large Canadian study conducted at ICES, in collaboration with
cardiologists and researchers from Sunnybrook Health Sciences Centre and the
University of Toronto, looked at over 3,700 unique matched pairs of Ontario
patients who received drug-eluting stents (DES) or more conventional bare
metal stents (BMS) during angioplasty. Using data from the Ontario Cardiac
Care Network's (CCN) population-based angioplasty registry, and accounting for
differences in patient characteristics, investigators analyzed the outcomes of
patients having angioplasty in Ontario between December 2003 and March 2005
for the 'real-world' effectiveness of DES. The results:

    
    -   DES reduced the need for a second procedure to unblock or bypass a
        clogged artery by 30% relative to BMS, from 10.7% to 7.4%.
    -   After 3 years of follow up, mortality was reduced for DES patients
        (5.5%) relative to BMS (7.8%).
    -   After 2 years of follow up, rate of heart attack for DES patients was
        marginally but not significantly higher at 5.7% vs. 5.2% in BMS
        patients.
    -   The reduction in the need for repeat procedures (i.e. target vessel
        revascularization (TVR rate)) was greatest in patients with two or
        three risk factors (e.g. diabetes, small vessels, or long lesions)
        for renarrowing of the artery, whereas lower and intermediate risk
        patients did not have significant reductions in TVR rates.
    

    Co-Author, Dr. Eric Cohen, Medical Officer for CCN says, "Drug-eluting
stents have been at the centre of a very active worldwide debate regarding
issues of safety, degree of benefit and funding of a relatively expensive new
technology. This study will be very helpful to clinicians, administrators and
policy-makers in clarifying these issues as it confirms that using
drug-eluting stents in patients at high risk for renarrowing is both effective
and safe."
    Interventional Cardiologists use the tiny wire mesh tubes called stents
to help prop open narrowed arteries after angioplasty, an artery clearing
operation and a common medical procedure for treating angina and heart
attacks. Prior to the development of stents, more than 20% of angioplasty
patients required a second angioplasty or bypass surgery because of
renarrowing of their coronary arteries. Both bare metal and drug-eluting
stents enable blood to flow more easily through the artery by holding it open,
with drug-eluting stents also leaking drugs to prevent tissue re-growth from
re-clogging the arteries.
    ICES Sr. Scientist, Dr. Jack Tu who holds a Canada Research Chair in
Health Services Research at Sunnybrook Health Sciences Centre and the
University of Toronto, says, "Physicians implanting the devices need to ensure
patients who get a drug-eluting stent also take anti-clotting medication such
as aspirin and clopidogrel (antiplatelet therapy) for a minimum of one year
after the angioplasty procedure. This therapy reduces the risk of fatal blood
clots associated with drug-eluting stents. This prolonged period of
clopidogrel usage could explain differences between results in Ontario,
compared to those from other countries, such as Sweden. In our study, these
medications were made available to all elderly patients in Ontario, at minimal
cost, through the Ontario Drug Benefits Program for one year after the
angioplasty procedure."
    Since their introduction in 2003, more than six million heart patients
worldwide have received a drug-eluting stent (DES). The DES market is worth
$5 billion a year, costing about $2300 for a DES versus $700 for a bare metal
stent (BMS). The rate of DES use in countries like the United States was as
high as 90% but dropped to about 70% in the past year, after recent
controversy over safety. Recent studies from Europe and Sweden suggest DES may
increase mortality and heart attack after a coronary angioplasty. The rate of
DES usage in Ontario was on average 38% of all stents during the study period.
In 2003, the Ontario government approved the introduction of DES provincially,
conditional upon an independent evaluation of their effectiveness and
cost-effectiveness. Approximately 20,000 angioplasties are performed each year
in the province of Ontario.
    The study "Effectiveness and safety of drug-eluting stents in Ontario" is
in the October 4th issue of the New England Journal of Medicine. The study was
funded by operating grants from the Ontario Ministry of Health and Long-term
Care and a Canadian Institutes of Health Research Team Grant in Cardiovascular
Outcomes Research.

    Author affiliations: ICES (J.V.T., M.C., D.T.K., P.C.A., Y.H.) and
Sunnybrook Health Sciences Centre, University of Toronto (J.V.T., D.T.K.,
E.A.C.) - both in Toronto; McMaster University, St. Joseph's Healthcare,
Hamilton, ON (J.B., R.H., J.-E.T., G.B., R.G.); and Trillium Health Centre,
Mississauga, ON, (C.L.) - all in Canada.

    ICES is an independent, non-profit organization that uses
population-based health information to produce knowledge on a broad range of
health care issues. Our unbiased evidence provides measures of health system
performance, a clearer understanding of the shifting health care needs of
Ontarians, and a stimulus for discussion of practical solutions to optimize
scarce resources. ICES knowledge is highly regarded in Canada and abroad, and
is widely used by government, hospitals, planners, and practitioners to make
decisions about care delivery and to develop policy.





For further information:

For further information: Kristine Galka, Media Relations, ICES, (416)
480-4780 or cell (416) 629-8493, kristine.galka@ices.on.ca

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