A Medical Device Daily

The first results from the Medtronic (Minneapolis) OMNI Study were released at Heart Rhythm 2009, the annual congress of the Heart Rhythm Society (Washington) revealing that one out of six patients with implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy-defibrillators (CRT-Ds) to prevent sudden cardiac arrest (SCA), received potentially life-saving medical therapy – either in the form of anti-tachycardia pacing (ATP) or a shock for dangerously fast heart rhythms – within a period of two years following their implant. Further, the study showed that patients received therapy at similar rates, regardless of whether they meet current medical society guidelines.

The OMNI Study is the first large-scale, longitudinal registry to follow nearly 3,000 real-world device patients. This analysis includes 1,620 patients who received devices for primary prevention of SCA, 993 of whom meet current guidelines, and 389 patients that do not. Patients among both groups received therapy at roughly the same rate:

Some 66% of patients among the guideline group, and 71% among the non-guideline group received ATP therapy. 34% percent of patients among the guideline group, and 29% among the non-guideline group received a shock

While OMNI researchers recognize that physicians may interpret the medical guidelines differently to drive individual treatment decisions for their patients, OMNI was not designed to assess why patients who meet or do not meet guidelines received devices from their doctors.

In other HRS conference news:

• Hansen Medical (Mountain View California) showcased advancements to its Sensei Robotic Catheter System for electrophysiology (EP) procedures. The company demonstrated improvements in its user interface, catheter capabilities and design, and in imaging and mapping technology integration.

The company showed its new tactile vibration feature for its IntelliSense Fine Force Technology, which provides physicians with tactile feedback on proximal force for the first time with the Sensei system. As a result, physicians can now feel IntelliSense's force measurements through vibration of the Instinctive Motion Controller (IMC).

In addition, physicians saw a visual measure of force on the Sensei system's display monitor during EP procedures. With this new feature, physicians now have an improved tactile understanding of IntelliSense's measurements and force sensing during complex cardiac procedures. This advancement is important because a study suggests a link between the ability to measure force and the quality of electroanatomical maps.

Hansen Medical's technology is compatible with fluoroscopy, ultrasound, 3-D surface map and patient electroanatomical data. The two main components that comprise the Sensei system are the Artisan catheter and the ergonomically designed, remotely placed workstation. The physician workstation is adaptable to existing EP lab suites and imaging technologies and can be placed away from the field of direct radiation.

• TYRX (Monmouth, New Jersey), a developer of the commercialization of implantable medical-pharmaceutical devices, reported the initial, interim clinical results from its AIGISRX Antibacterial Envelope Retrospective Registry.

AIGIS is an anti-bacterial mesh envelope developed to deliver anti-microbial agents that help provide protection against infections associated with implanted pacemakers and cardioverter defibrillators. AIGIS also securely holds a pacemaker or ICD in order to create a stable environment when implanted in the body.

• CardioNet (Conshohocken, Pennsylvania) reported the launch of SomNet, a new clinical indicator available in the company's existing Mobile Cardiac Outpatient Telemetry (MCOT) system. Because many patients with cardiac disorders also suffer from common sleep disorders like sleep apnea, CardioNet believes that SomNet has the potential to identify patients with a high likelihood of such sleep disorders by measuring cyclic variation of heart rate (CVHR), a rhythm that is caused by repeated arousals from sleep due to such disorders.

"There is a high prevalence of sleep disorders like sleep apnea in the cardiovascular and arrhythmia population," said CEO Randy Thurman. "The data collected by SomNet is extremely valuable information that can be captured from our existing MCOT ECG signal. If clinically appropriate, physicians may choose to refer patients with CVHR patterns to sleep centers for further diagnostic testing, to determine if they have sleep apnea or another serious sleep disorder."

In an 80-patient study, Phyllis Stein, PhD, research associate professor of medicine at Washington University School of Medicine (St. Louis), found that automated identification of clinically relevant CVHR is feasible using CardioNet's MCOT system. The study compared MCOT automatic analysis of CVHR patterns versus a human expert's direct analysis of plots of HR patterns for measuring clear (large amplitude) CVHR. Findings showed similar specificity and positive predictive value measures between MCOT and human expert analysis, with slightly lower sensitivity measures for the automated analysis.

• Endosense (Geneva, Switzerland) reported the release of acute clinical results from the TOCCATA (TOuCh+ for CATheter Ablation). The results of the 76-patient, multi-center study confirm the feasibility, safety and value of Endosense's TactiCath force-sensing ablation catheter during catheter ablation. The first and only force-sensing ablation catheter, TactiCath gives physicians a real-time, objective measure of contact force during the catheter ablation procedure. The TactiCath was granted the CE mark this month.

The TOCCATA trial was designed to evaluate the safety and value of force-sensing in the catheter ablation procedure. Conducted at eight centers in five countries, the study was led by principal investigator Karl-Heinz Kuck, MD, with participation from 20 additional highly experienced investigators. Enrollment in TOCCATA was completed in February, with a total of 76 patients (42 right SVT and 34 paroxysmal atrial fibrillation [AF]). Safety and treatment efficacy have been proven for the SVT group, which has reached the study endpoints. Data from the AF group is anticipated by the end of May.

During the study, operators were given full access to real-time force information during catheter ablation but were blinded to force information during force assessment. Key findings, extracted from 185 hours of force contact data, are the subject of two separate Heart Rhythm 2009 presentations by Dr. Kuck and TOCCATA investigator Dipen Shah, MD

• eCardio Diagnostics (Woodlands, Texas) reported the launch of its new Atrial Fibrillation Information System (AFIS). AFISis an informatics solution that presents a longitudinal view of atrial fibrillation and tachyarrhythmic patients for teaching, research or clinical management. It is the first comprehensive software application to gather all associated clinical information in one place for AF patient management.

Designed specifically to meet the needs of electrophysiologists in academic medicine, AFIS captures imaging, monitoring, procedural reports, clinic notes and patient history to provide clinicians with the most longitudinal data set on which to render treatment decisions.