Cardima
REVELATION® Tx Microcatheter Ablation System
Device Design
The Cardima®
Inc., REVELATION® Tx Microcatheter with NavAblator RF Ablation
System is intended for the treatment of atrial fibrillation (AF) in patients
with drug refractory paroxysmal AF by mapping, pacing, and ablating in the
right atrium.
The design of
the REVELATION Tx is based on angioplasty guidewire technology and uses small,
coiled electrodes that are highly flexible and conform to the anatomy of the
atrium to deliver RF energy at a higher density than conventional (“hot tip”)
RF ablation catheters (including the NavAblator). This technology produces lesions that are equivalent in depth to
those created with a conventional RF ablation catheter but are thinner and
require less RF energy to create them.
Study
Design
The safety and effectiveness
of this system for the stated intended use has been investigated over a
three-phase (IIa, IIb and III) prospective, multi-center clinical trial with
the patient serving as his own control.
The study population included patients with no significant structural
heart disease and drug refractory, paroxysmal AF, with a documented episode
frequency of at least 3 symptomatic episodes per month as documented by event
monitoring devices over 30 days.
The primary
endpoints for this study were evaluated at six months post treatment in >80
patients. The primary endpoints were
(1) reduction of 50% in frequency of spontaneous symptomatic AF episodes (75%
reduction in patients with ≤ 4 episodes/month) and (2) the incidence of
major adverse events. The secondary
clinical endpoint was quality of life based on two recognized instruments,
general health measured by the SF-36 and symptoms and severity of AF measured
by the Atrial Fibrillation Severity Scale (AFSS). Clinical (patient) success was defined as a reduction in
frequency of symptomatic episodes compared to baseline while maintained on the
same anti-arrhythmic drug regimen or reduced dosage.
Results
Two hundred
seventeen (217) patients were screened, 120 treated, and 6-month follow up data
have been compiled for 81 patients showing an overall success rate of 85.2% (69__/__81) in meeting
the primary endpoint of a reduction in frequency of symptomatic AF episodes of
at least 50% after 6 months. In
addition, 54.3% (__/__)(44/81) of these
subjects reported a 100% reduction in episodes at 6 months. Patient Success
was demonstrated for 62% of the subjects who had both a decrease in episode
frequency and either maintained the same anti-arrhythmic drug regimen or
experienced a decrease in dosage. The
rate of major complications was 3.4% and included a pericardial effusion, a
sinus node injury, a stroke, and an AV fistula. Other adverse effects were largely consistent with cardiac catheterization
procedures, including skin burns, sore throat, back pain, etc. Minor complications numbered 53 for 31
subjects (27%).
Patient Success
was demonstrated for at least 60% (50/81) of the subjects who had both a decrease in episode
frequency and either maintained the same anti-arrhythmic drug regimen or
experienced a decrease in dosage.
These results
were accompanied by significant improvements in quality of life for study
subjects who reported improvements in all categories of quality of life and
statistically significant (p<0.05, paired t-test) improvements for six of
the eight mean scores of the SF-36.
Subjects also reported overall improvement of approximately 25%
(p<0.0001) and highly statistically significant improvements in episode
frequency and reduced episode duration (p<0.0001 and p<0.001,
respectively) according to the AFSS scores.
Conclusion
These results indicate acceptable
effectiveness and safety and offer the benefit of a less invasive approach to
treating AF