30-day home-based monitoring key to detection of hidden risk factor
HONOLULU, Hawaii, Feb. 7, 2013 /CNW/ - A significant portion of people
with unexplained strokes has silent atrial fibrillation, researchers in
16 Canadian stroke centres discovered as part of the largest study and
first randomized clinical trial of heart monitoring in stroke patients.
Atrial fibrillation, an irregular heart rhythm, is known to cause some
of the most disabling, deadliest, and most costly types of strokes, but
it can be a silent risk factor that evades detection.
The three-year EMBRACE trial involving 572 patients was presented today
at the International Stroke Conference by lead researcher Dr. David
Gladstone of the University of Toronto Department of Medicine. He
reported that with a new strategy of advanced heart monitoring, one in
six people with an unexplained stroke or transient ischemic attack
(TIA) were found to have silent atrial fibrillation that would have
otherwise gone undiagnosed and untreated by standard methods.
"This study provides the strongest evidence to date to support intensive
heart monitoring in patients with unexplained strokes or mini-strokes,"
according to the American Stroke Association, which highlighted the
Canadian research as a late-breaking research development at the
Atrial fibrillation is a risk factor for stroke because it can promote
the formation of blood clots in the heart that can travel to the brain.
It is important to detect because it can be effectively treated with
certain anti-clotting medications, which cut the risk of clots and
strokes by two-thirds or more.
Dr. Gladstone, based at Toronto's Sunnybrook Research Institute and
Sunnybrook Health Sciences Centre, said the Canadian Stroke
Network-funded study has implications for improving stroke
prevention."The hope is that earlier detection and treatment of atrial
fibrillation may lead to more strokes prevented and more lives saved."
The challenge has been that atrial fibrillation is often hard to detect
because the irregular heartbeat may last for just a few minutes at a
time, after which the heart reverts back to its normal rhythm. Unless
an individual is wearing a heart monitor at the time it occurs, the
diagnosis is usually missed. In practice, stroke patients have
traditionally received short-duration heart monitoring for 24 or 48
hours to screen for atrial fibrillation. However, advances in heart
monitoring technology now make it possible for patients to be screened
at home for much longer periods.
The trial studied patients who had a recent stroke or mini-stroke of
unknown cause and in whom standard heart monitoring failed to detect
atrial fibrillation. Participants were randomized into two groups: the
first received an additional 24 hours of monitoring, and the second
received continuous monitoring for 30 days at home using a new
technology chest electrode belt that automatically detects episodes of
In the study, prolonged monitoring picked up a new diagnosis of atrial
fibrillation in 16 per cent of patients, compared to three per cent of
those who only received an additional 24 hours of monitoring. The
enhanced detection led to significantly more patients being prescribed
stronger anti-clotting medications to prevent recurrent strokes.
This research is relevant to an estimated three million people worldwide
every year who suffer strokes of unknown cause. It will force experts
to rethink the diagnostic and treatment approaches for such patients
with so-called 'cryptogenic' strokes, which have remained a medical
conundrum for years. The implication is that a half-million stroke
patients each year may have untreated atrial fibrillation and not know
"These results are practice-changing," says Dr. Antoine Hakim, CEO and
Scientific Director of the Canadian Stroke Network. "This study really
shows that the harder you look, the more atrial fibrillation you will
The Canadian Stroke Network (www.canadianstrokenetwork.ca) is a national research network headquartered at the University of
Ottawa. It includes scientists, clinicians and health-policy experts
committed to reducing the impact of stroke.
SOURCE: CANADIAN STROKE NETWORK
For further information:
Cathy Campbell, Canadian Stroke Network, 613-852-2303 (cell)
firstname.lastname@example.org (at the International Stroke Conference)
Nadia Norcia Radovini, Sunnybrook Health Sciences Centre, 416-671-9147(cell)
email@example.com (to arrange patient interviews)