Insulation Failure in St. Jude Riata Leads

Summary

A recent study evaluated the Manufacturer and User Facility Device Experience (MAUDE) database, which contains reports of adverse events involving medical devices6,9. The FDA updates the database every two months. A total of 107 Riata leads with reported inside-out insulation breaks were found, of which 105 were available for analysis. The average age of the leads was 62.1+/-18.6 months. A total of 226 insulation defects were found with 143 inside-out insulation abrasions. Twenty-eight of the 105 leads (26.7%) had inside-out insulation defects underneath one or more of the high voltage-shocking coil. Of these, 23 were 8F and five were 7F Riata ST leads. Exposed cables or conductors were present in 32 leads and six leads had melted cables, presumably due to one or more high voltage shocks. 22 of the 43 leads assessed (51.2%) also had abraded ETFE cable coating exposing the conductor. Noise and other sensing issues were the most common signs of failure. Seven leads were found to have externalized cables and five exhibited electrical abnormalities. 31 patients (29.5%) experienced inappropriate shocks of which 41% had abraded cables.

A critical decision facing physicians is how to screen and manage patients who are found to have externalized cables. Externalized cables on fluoroscopy may precede any electrical abnormalities. Also noise may not be detected on all ICD models. A recent case report suggested that changes in lead parameters might be transient and may be missed. The lead may function normally as the high-voltage and pace-sense cables are covered with ETFE, which serves as the second insulating barrier. As this is a very thin layer (0.0015 inches) the reliability of this to withstand a high-energy shock is unknown. This may lead to failure of appropriate therapy for life threatening arrhythmias.

The aim of this study is to screen patients with ICD leads that potentially could have multiple different failure mechanisms, including inside-out insulation breaks, to develop a novel new algorithm and methods to detect these defects, thereby enabling physicians to prevent complications from failure of these leads.

It is hypothesized that current monitoring tools are insufficient for detecting the sometimes transient electrical failures of the Riata family of leads, and that additional device diagnostic information in combination with fluoroscopy may improve detection of electrical failures.

Conditions

• Implanted With Any Currently (and Any Future) FDA-approved Medtronic ICD or CRT Device
• to Which is Attached a St. Jude Riata Lead

Interventions

PROCEDURE

fluoroscopy

Fluoroscopic evaluation of three different views (left anterior oblique, right anterior oblique and anterior/posterior) and magnification will be performed to check for externalized cables at 15 frames per second using the best visualized angle per screening electrophysiologist.

PROCEDURE

synchronized high-voltage shock

If fluoroscopic evaluation shows externalized conductors or if patient is deemed high-risk, the patient will be consented for synchronized high voltage shock through his/her device. This will be done in the non-invasive electrophysiology lab with conscious sedation as is done during defibrillation threshold testing. For patients undergoing a generator (ICD) change as part of standard of care, performance of synchronized, high-voltage shock will be performed at the discretion of the electrophysiologist.

PROCEDURE

Holter monitor

Participants will be given a 24-hour Holter monitor at baseline and once annually, and will be followed at least every three months throughout the study. Participants who are found to have an electrical abnormality at any point during the study may be given a 24-hour Holter monitor if it is believed that this procedure will provide clinically useful information regarding the integrity of the lead.

Sponsors & Collaborators

• Hartford Hospital

  lead OTHER

Principal Investigators

• Steven Zweibel, MD · Hartford Hospital

Study Design

Allocation

NA

Purpose

SCREENING

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2013-07-31

Primary Completion

2018-04-30

Completion

2019-01-31

Countries

• United States

Study Locations