Pediatric Lead Extractability and Survival Evaluation (PLEASE)

Overview

This is a randomized, prospective clinical trial comparing 2 different types of implantable cardioverter defibrillator (ICD) leads in children and patients with congenital heart disease. ICD lead survival in this patient group is particularly suboptimal, and lead extraction is technically difficult and carries a substantial morbidity risk. Recently, improved ICD lead designs have been released and are currently being utilized in patients. The main aim of the study is to determine if either type of lead performs better in terms of implantation electrical characteristics, long-term survival without breaking, and ease of extractability.

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.