Pediatric Lead Extractability and Survival Evaluation (PLEASE)

The recognition that ICD therapy in children can be life-saving, as well as the development
of smaller devices and leads, are resulting in increased ICD implantation in the pediatric
and young adult populations. However, ICD lead survival in this patient group is suboptimal.
Lead extraction is technically difficult and has substantial morbidity. Recently, improved
ICD lead designs have been released and are currently being utilized. While the development
of transvenous ICD leads has allowed for less invasive implantation, the long-term presence
of these leads carries some risks. When a lead becomes infected or causes patient morbidity,
it must be removed. Because of the larger caliber of ICD leads and the presence of
uninsulated shocking coils, non-functional ICD leads usually warrant removal to avoid future
mechanical or electrical lead interactions. The larger size of ICD leads is of concern in
this younger population, particularly with regard to avoiding the accumulation of implanted
hardware. The principal indication for lead revision in children and young adults is lead
malfunction, commonly related to patient growth and increased physical activity in this
younger population. The removal of chronic indwelling pacer or ICD leads is not trivial. Scar
tissue begins to bind transvenous leads to the endothelial surface several weeks after
implantation, and this fibrous adherence progresses over time, exacerbated by high-energy
shock delivery. In children and younger adult ICD recipients, exuberant lead scarring is
prevalent, particularly in the regions of venous entry, high voltage shocking coils, and the
lead tip. Transvenous lead extraction has been facilitated by the use of telescoping sheaths
and powered sheaths that can be advanced over the lead to disrupt scar tissue and free the
lead from the endothelium.

The 2 ICD lead types to be compared (thin ICD leads versus ePTFE-coated leads) in the
proposed study are at clinical equipoise. Both types are believed to be improved over prior
generation ICD leads. However, a direct comparison has not been performed. As the pediatric
and congenital heart disease patient subgroup is younger than the average ICD patient
population, they will have greater likelihood of long-term survival, and therefore, the
issues of lead survival, durability, and extractability are critically important. While these
themes are important for all ICD patients, they are particularly germane for younger patients
who have more active lifestyles and are, in general, expected to outlive their ICD leads.

This study will prospectively assess the improvements in ICD lead design, specifically
comparing a Gore ePTFE coating and thinner caliber ICD leads in pediatric and congenital
heart disease population.

Specific Aim #1: To prospectively evaluate the long-term performance of modern-generation ICD
leads in pediatric and congenital heart disease patients.

Specific Aim #2: To determine the potential beneficial effects of two improvements in ICD
lead design - Gore ePTFE coil coating and thinner lead diameter in pediatric and congenital
heart disease patients.

Specific Aim #3: To directly compare the safety and efficacy of these new ICD lead
technologies in terms of extractability in pediatric and congenital heart disease patients.

The primary hypothesis is that improved lead designs and smaller diameter leads will
demonstrate benefit in survival and extractability. The primary outcome variables will
include: a) ICD lead functionality and performance by subtype, b) inappropriate shocks due to
lead issues, c) lead extractability by subtype (Gore-coated versus thin leads).

Secondary outcomes include comparison of implant electrical parameters, patient morbidity and
mortality, comparing each new lead type with each other and against historical pediatric
controls with standard transvenous ICD leads.

Inclusion Criteria:

- Patients will be eligible for study enrollment at the time of implantation of a new
ICD and transvenous ICD lead.

- All patients under the age of 21 years at the time of initial ICD implantation, or
those patients with congenital heart disease and an indication for ICD implantation
are eligible for participation.

Exclusion Criteria:

- Patients who have existing ICD leads in place.

- Patients with expected survival less than 1 year.

- Patients who cannot be expected to participate in follow-up visits.

- Patients receiving an epicardial or subcutaneous ICD (without transvenous ICD lead).