New Method Significantly Improves Treatment Of Severe Heart Condition, Canadian-led Study Finds

Main Category: Heart Disease
Also Included In: Cardiovascular / Cardiology
Article Date: 18 May 2009 - 6:00 PDT

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The results of an international study led by a Toronto-area doctor were unveiled today that show there's a more effective way to treat patients with a severe arrhythmia, or irregular heartbeat, than the current treatment methods.

The findings were presented in Boston at Heart Rhythm 2009, the annual Heart Rhythm Society's Scientific Sessions, by Dr. Atul Verma, Electrophysiologist at Newmarket-based Southlake Regional Health Centre, who designed and spearheaded the study.

The trial followed 108-patients at four Canadian hospitals - Southlake Regional Health Centre in Newmarket, Hamilton Health Sciences in Hamilton, Montreal Heart Institute in Montreal and Royal Jubilee Hospital in Victoria - and four European cardiac centres in Norway, Spain and Italy, over a one-year period. It compared three different methods of treating patients suffering from atrial fibrillation (AF), the most common heart rhythm disturbance, and found that a combination of two treatment methods yielded significantly better patient outcomes.

Affecting millions of people worldwide, including 200,000 Canadians, AF is a condition in which the upper chambers of the heart beat rapidly and erratically, affecting the heart's ability to adequately pump blood to its lower chambers and the rest of the body. The condition is responsible for 15 to 20 per cent of all strokes, is a contributor to heart failure and is a leading cause of hospitalizations, causing debilitating symptoms and poor quality of life.

Medications to control the condition are often ineffective, so ablation - or burning inside the heart - is often used. The trial - sponsored by St. Paul, Minn.-based St. Jude Medical and called Substrate versus Trigger Ablation for Reduction of Atrial Fibrillation (STAR-AF) - compared three approaches to ablation: the traditional method of burning the tissue surrounding the pulmonary veins (an area that has shown to transmit electrical signals that trigger AF), creating a scar that blocks abnormal signals to the heart; a newer, automated approach of targeting and burning "hot spots" in the heart identified by electrical signals called "fractionated electrograms"; and a therapy combining both of these methods.

The study - which followed patients with intermittent, recurring or persistent AF who had been unresponsive to medication - found that after one treatment, the combination therapy demonstrated significantly higher freedom from AF, explained Dr. Verma. Seventy-four per cent of patients who received the combination treatment showed no signs of AF after the one-year study, compared to 47 per cent who received only ablation of the pulmonary vein tissue and 29 per cent who underwent only "hot spot" therapy. What's more, 94 per cent of patients who received the combined therapy remained off of any anti-arrhythmic medications at the end of the 12-month follow-up period.

"While many unanswered questions remain about the origins of and best treatment options for AF, the trial's results indicate that perhaps traditional pathways are not the optimal ones," said Dr. Verma. "The results demonstrate an incremental benefit for patients who historically may have undergone only method of treatment and will help us to refine our approaches to ablating AF for better patient outcomes in the future."

First introduced in 1999, ablation has been applied by cardiac specialists across the country over the last decade, but the two techniques have never been compared in terms of patient outcomes, Dr. Verma added, explaining that currently, ablation of the heart tissue alone often results in either recurrence of AF or another complicated arrhythmia that requires additional patient care.

"Ablation is a relatively new therapy and is constantly improving," Dr. Verma said. "While there is still more research to be done, the results of the study will enable us to keep building on the techniques and deliver better and better patient outcomes," he said, adding that future research on a larger scale is planned.

About Heart Rhythm 2009

Heart Rhythm 2009 takes place May 13-16 at the Boston Exhibition and Convention Center. The meeting is the most comprehensive educational event on heart rhythm disorders, offering approximately 250 educational opportunities in multiple formats. The world's most renowned scientists and physicians will present a wide range of heart rhythm topics including cardiac resynchronization therapy, catheter ablation, cardiac pacing and heart failure and the latest technology, including state-of-the-art pacemakers and defibrillators.

Source
Southlake Regional Health Centre

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