St Jude Medical Implantable Cardiac Devices when used with Merlin programmer and version 17.2.2 software

Health professionals are advised that St Jude Medical Australia, in consultation with the TGA, has issued a hazard alert regarding its Implantable Cardiac Devices (ICDs, including Cardiac Resynchronisation Therapy Defibrillators (CRT-Ds)) when reprogrammed with the Merlin Programmer using software version 17.2.2.

ICDs are implantable medical devices that use small electrical impulses to treat abnormal heart rhythms. CRT-Ds are ICDs that also coordinate the beating of the left and right ventricles to improve the heart's blood pumping ability. The Merlin programmer is used by health professionals to monitor the performance and adjust the settings of these ICDs and CRT-Ds.

It has been identified that a software fault with version 17.2.2 can potentially lead to ICDs/CRT-Ds delivering insufficient therapy during automated defibrillation in some circumstances. This fault only occurs when the devices are programmed to a specific setting for arrhythmia (fast heart rate) detection.

The affected software version 17.2.2 was released in September 2013 and this issue only affects certain families of St Jude ICDs/CRT-Ds that have been reprogrammed using the Merlin Programmer since then and only when the implanted device is programmed to a specific setting (see the 'Technical information' and 'Affected devices' sections below for more details).

St Jude advises that a new version of the software to address these issues should be released in February.

Information for consumers

If you, or someone you care for, have received an affected ICD or CRT-D implant your cardiologist should contact you for an appointment. If you haven’t been contacted and you are concerned about this issue, contact your treating cardiologist or clinician for advice.

If you have an affected device it can be reprogrammed to one of the unaffected monitoring modes while waiting for the updated software to be released.

Information for all health professionals

If you are treating a patient who has an implanted St Jude ICD or CRT-D device affected by this recall, refer them to their treating cardiologist.

Information for cardiologists

St Jude has written to cardiologists who are using affected Merlin programmers, providing further information about this issue. While waiting for the software update, cardiologists are advised:

• To review patient records to identify patients implanted with affected St Jude Medical ICD/CRT-D devices or seen in clinic starting in September 2013. The programmer software version is printed on the bottom of each report page. For patients identified to have been programmed to a single VF detection zone with the 17.2.2 software you should schedule an immediate follow-up visit. For patients programmed to two- or three- zone detection criteria, no action is required.
• For patient devices programmed with 17.2.2 software, the new software version 17.2.3 will correct this issue and is expected to be available by February 2014. St Jude Medical will arrange for you to obtain the 17.2.3 software and install it on your programmer. Programming any parameter with the updated software will reset the ICD/CRT-D to normal function.
• If a patient is seen before the 17.2.3 software is installed, program the device to a two- or three-zone configuration, even if one of the zones is strictly a monitor zone. This will resolve the issue when using a programmer with 17.2.2 software.

If you need further information concerning this issue, contact your St Jude Medical representative.

Technical information

In September 2013, St. Jude Medical released the Merlin Programmer software version 17.2.2 rev. 0 (referred to as 17.2.2) as an upgrade to existing programmers. Testing has shown that, when using a programmer with the 17.2.2 software, an incorrect value for sinus redetection can occur when a device is programmed to a single ventricular fibrillation (VF) detection zone, potentially affecting the high-voltage therapy delivery sequence. When using the 17.2.2 software and any parameter is programmed as part of a single VF detection zone configuration, the sinus redetection value will be inappropriately set to zero milliseconds. As a result, any intrinsic activity following the first shock will be considered a 'sinus rate' and the device will diagnose 'return to sinus'. Therefore, if the arrhythmia was not terminated by the initial high voltage therapy, the ongoing arrhythmia would be considered a new episode, causing the next high voltage therapy to also be delivered at the first programmed energy level. For example, if the first shock is programmed to 20 joules and subsequent shocks are programmed to higher energy values, the only HV therapy the patient would receive, if the arrhythmia continues and is redetected, would be 20 joules, rather than the increasing HV energy levels as programmed.

The anomaly can be introduced during programming of certain families of St Jude Medical ICD/CRT-D devices (see the 'Affected devices' section below for more details). The anomaly is not present when a device is programmed to a two- or three-zone configuration.

Affected devices

ICDs and CRT-Ds that will be affected if programmed to a single VF detection zone by a Merlin programmer with 17.2.2 software.

Reporting problems

Consumers and health professionals are encouraged to report problems with medical devices. Your report will contribute to the TGA's monitoring of these products. For more information see the TGA Incident Reporting and Investigation Scheme (IRIS).

The TGA cannot give advice about an individual's medical condition. You are strongly encouraged to talk with a health professional if you are concerned about a possible adverse event associated with a medical device.