Irregular heart rhythm a major clue to unexplained strokes, Canadian study finds

30-day home-based monitoring key to detection of hidden risk factor

HONOLULU, Hawaii, February 7, 2013 /Canada NewsWire/ - 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 meeting.

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 atrial fibrillation.

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 it.

"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 find."

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.

Recommendations will Prevent Stroke Patients from Falling Through Cracks

New website provides accessible information on optimal stroke care

OTTAWA, December 8, 2010 /Canada NewsWire/ - The 2010 Canadian Best Practice Recommendations for Stroke Care emphasize the need to prevent stroke patients from falling through the cracks as they move from the ER to in-hospital care to rehabilitation therapy and back to the community. The recommendations were released today by the Canadian Stroke Network and the Heart and Stroke Foundation of Canada.

"The adoption of these best practices will ensure stroke patients and families have rapid and seamless access to appropriate stroke services across the continuum and that they are well supported through these transitions," says Patrice Lindsay, PhD, Director of Performance and Evaluation at the Canadian Stroke Network and one of the project leaders.

Among new recommendations:

...Blood pressure should be maintained at a level that is consistently lower than 140/90;

...Because atrial fibrillation (irregular heartbeat) increases stroke risk, patients with this condition should be closely monitored and the use of new drug therapies should be considered;

...Patients who have a mini-stroke (transient ischemic attack) should be referred immediately to a stroke specialist at a prevention clinic or to an emergency department due to increased risk of a major stroke;

...There should be more widespread use of telestroke - long-distance video and data hookups - between stroke specialists and communities where on-site stroke care does not exist; and
Improved hospital discharge programs are needed, as well as better community services to enable people to return home sooner from hospital.

Thanks to earlier guidelines released in 2006 and 2008, more communities in Canada have an organized emergency response to stroke, stroke prevention clinics, specialized hospital stroke units, and improved rehabilitation services, all of which have been shown to save lives and reduce disability.

This is first time that this information has been pulled together in an easy-to-search and smart-phone friendly website - www.strokebestpractices.ca. The website includes resources to improve stroke and emergency services and to measure their effectiveness. It also includes a patient's guide to optimal stroke care.

"Stroke is the third leading cause of death in Canada yet most strokes are preventable and treatable," says Bobbe Wood, CEO of the Heart and Stroke Foundation of Canada. "Increasing awareness is a key part of the Canadian Stroke Strategy. The best practices website will provide optimal stroke resources and tools to the public and professionals such as physicians, emergency personnel, nurses, rehabilitation specialists and health policymakers."

The Canadian Best Practice Recommendations for Stroke Care was developed as part of the Canadian Stroke Strategy, an initiative of the Canadian Stroke Network and Heart and Stroke Foundation of Canada to improve stroke care for people across the country. There are about 50,000 new strokes in Canada each year and 315,000 Canadians living with the after-effects of a stroke.

The Canadian Stroke Network (canadianstrokenetwork.ca) brings together Canada's leading scientists and clinicians to reduce the physical, social and economic impact of stroke on the lives of individual Canadians and on society as a whole. Headquartered at the University of Ottawa, the Canadian Stroke Network is one of Canada's Networks of Centres of Excellence.

The Heart and Stroke Foundation of Canada (heartandstroke.ca), a volunteer-based health charity, leads in eliminating heart disease and stroke and reducing their impact through the advancement of research and its application, the promotion of healthy living, and advocacy.

The Canadian Stroke Strategy (www.canadianstrokestrategy.ca) is a joint initiative of the Canadian Stroke Network and the Heart and Stroke Foundation of Canada. The goal of the Canadian Stroke Strategy is to help support an integrated approach to stroke prevention, treatment and rehabilitation in every province and territory by 2010.