Benefits of Catheter Ablation with the NAVISTAR THERMOCOOL Catheter Sustained for One Year in the Treatment of Symptomatic, Paroxysmal Atrial Fibrillation

Quality of Life Measures Greater for Patients Receiving Ablation vs. Drug Therapy

BOSTON--(BUSINESS WIRE)--May 14, 2009 - In final, one-year results of a multicenter randomized clinical study, catheter ablation demonstrated significantly better outcomes compared to anti-arrhythmic drug (AAD) therapy for the treatment of drug refractory recurrent symptomatic paroxysmal atrial fibrillation. Atrial fibrillation, or AFib as it is more commonly referred to, is the most prevalent cardiac arrhythmia (heart rhythm disorder), affecting an estimated 20 million people worldwide. It is also one of the most common causes of stroke.

In a presentation here today during the Late Breaking Clinical Trials session at Heart Rhythm 2009, patients receiving cardiac ablation with the NAVISTAR® THERMOCOOL® Catheter, manufactured by Biosense Webster, Inc., were significantly more likely to be free of recurring AFib after initiation of treatment and experienced fewer serious adverse events than those receiving AAD therapy.

In addition, patients receiving catheter ablation reported markedly fewer symptoms and substantially improved quality of life compared to those receiving AAD.

“The final results of this trial provide electrophysiologists and their AFib patients with rigorous data demonstrating the significant benefits of catheter ablation compared to ongoing treatment with medical therapy,” said David Wilber, M.D., Primary Investigator of the study and the George M. Eisenberg Professor of Cardiovascular Sciences and Director, Division of Cardiology, Loyola University Medical Center in Maywood, Illinois. “In addition, this study shows that patients report an improved quality of life following ablation therapy, which is an important measure of the benefits of catheter ablation on one's activities of daily living.”

In addition to his role as Primary Investigator, Dr. Wilber is compensated for his services as a member of the Company's scientific advisory board and provides other consulting services.

“We are pleased that the complete 1-year post-ablation results of this trial further substantiate the safety and effectiveness of ablation with the NAVISTAR® THERMOCOOL® Catheter in patients with AFib,” said Marcia Yaross, Ph.D., Vice President, Clinical, Regulatory and Health Policy, Biosense Webster, Inc. “Further, new analyses presented today demonstrate that 63% of the ablation patients in this study remained free of any observed atrial arrhythmia during the evaluation period, not just symptomatic AFib recurrence, vs. only 17% of those treated with AADs.”

This clinical trial was a randomized, unblinded and controlled evaluation of symptomatic, paroxysmal AFib patients who were refractory to at least one AAD and had at least three episodes of AFib in the six months prior to randomization. A total of 167 patients were enrolled from 19 sites throughout the world and the primary effectiveness endpoint (chronic success) was freedom from documented symptomatic AFib recurrence following procedural endpoint confirmation and absent new AAD use or repeat ablation outside of protocol-defined criteria.

Chronic success was achieved by 66% for patients receiving NAVISTAR® THERMOCOOL® Catheter ablation at the end of the study effectiveness evaluation period, which is significantly superior (p<0.001) to the 16% of patients treated with AAD. The THERMOCOOL® Catheter ablation group also demonstrated a substantial reduction in symptomatic atrial arrhythmia (including AFib) recurrence compared with patients treated with AAD (70% vs 19%, p<0.001).

Additionally, the NAVISTAR® THERMOCOOL® Catheter ablation group demonstrated an excellent safety profile with no device-related serious adverse events such as death, heart attack, stroke, cerebrovascular accident, heart block or atrial perforation within seven days post ablation. Importantly, there was no clinically significant pulmonary vein stenosis in patients receiving ablation, and the incidence of serious adverse events in the THERMOCOOL® Catheter group was observed to be approximately half that in the AAD group (5% vs. 9%).

The NAVISTAR® THERMOCOOL® Catheter and the EZ STEER® ThermoCool®/NAV Catheter are the only ablation catheters approved by the U.S. Food and Drug Administration for the treatment of drug refractory recurrent symptomatic paroxysmal atrial fibrillation when used with compatible three-dimensional electroanatomic mapping systems.

The NAVISTAR® THERMOCOOL® Catheter is also approved in the United States for the treatment of Type 1 atrial flutter, and recurrent drug/device refractory sustained monomorphic ventricular tachycardia due to prior myocardial infarction (heart attack), two types of cardiac arrhythmia.

AFib: Growing Statistics and Current Treatment Options

AFib is the most prevalent arrhythmia, affecting between 2.3 to 5.6 million adults in the United States, and is a leading cause of stroke among people 65 years and older. Worldwide, it is estimated that 20 million people have AFib, yet fewer than 80,000 are treated through ablation. The public health implications of AFib are a growing concern because those with the condition are at an increased risk of morbidity and mortality as well as a reduced quality of life.

Most patients with AFib today are treated with AADs even though about half of them are refractory to these drugs. During cardiac ablation, a catheter is inserted into the heart and energy is delivered through the catheter to those areas of the heart muscle causing the abnormal heart rhythm. This energy “disconnects” the pathway of the abnormal rhythm.

Cardiac ablation is an important therapeutic tool in treating arrhythmias. It is the standard of care for ˜simple' arrhythmias, like Wolff-Parkison-White Syndrome, Type I atrial flutter and atrioventricular nodal re-entry tachycardia (AVNRT). It is increasingly being used for more complex arrhythmias like ventricular tachycardia and atrial flutter.

In 2006, the leading medical societies including the American Heart Association, American College of Cardiology and the European Society of Cardiology recognized catheter ablation as second-line therapy for AFib.

About Biosense Webster, Inc.

Biosense Webster, Inc., a Johnson & Johnson company, pioneered electrophysiology diagnostic catheters more than 30 years ago and continues to lead the industry as an innovative provider of advanced diagnostic, therapeutic and mapping tools. As the leader in navigation systems and ablation therapy, Biosense Webster, Inc.'s technology includes the largest installed base of navigation systems worldwide in leading hospitals and teaching institutions. With proprietary products such as the CARTO® XP System, the CARTOSOUND™ Image Integration Software Module, the THERMOCOOL® Irrigated Tip Catheter and the LASSO® Circular Variable Mapping Catheter, the company is changing the way electrophysiologists diagnose and treat arrhythmias.

For more information about Biosense Webster, visit www.biosensewebster.com.

Photos/Multimedia Gallery Available: http://www.businesswire.com/cgi-bin/mmg.cgi?eid=5965020&lang=en

Contact: Biosense Webster, Inc.
Christopher Allman
(m) 305-586-6024

Posted: May 2009

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