Insulation Failure in St. Jude Riata Leads

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.

This will be a prospective, single-center study. Patients who consent to participate will be
enrolled for up to three years.

This study offers the potential of direct benefit to the patient and indirect benefit for
future users of the ICD systems. This study may identify inside-out insulation breaks and
prevent impending lead failure. Additionally, analyses of the data collected as part of this
study may help to develop an "electronic footprint" or pattern to remotely identify
inside-out insulation breaks in all ICD leads Potential risks include exposure to radiation
from a fluoroscopic exam of the lead and receiving a synchronized ICD shock.

Inclusion Criteria:

- Male or female

- Age ≥18

- Implanted with any Medtronic Protecta® VR/DR/CRT, XT-VR/DR/CRT, Secura®, Virtuoso®,
Maximo II®, Concerto® VR, Evera® or Viva® (and any future FDA-approved Medtronic ICD)
device to which is attached a St. Jude Riata lead (Models 1560, 1561, 1562, 1570,
1571, 1572, 1580, 1581, 1582, 1590, 1591, 1592, 7000, 7001, 7002, 7010, 7011, 7040,
7041, 7042)

- Willing and able to sign informed consent

Exclusion Criteria:

- Age <18

- ICD that does not use a Riata lead

- Riata lead not connected to Medtronic Protecta® VR/DR/CRT, XT-VR/DR/CRT, Maximo II®
Secura®, Virtuoso®, Concerto® VR, Evera® or Viva® (and any future FDA-approved
Medtronic ICD) device

- Unwilling or unable to sign informed consent