Table 2. Patients Who Did NOT Receive Pre-Implant Circulatory Rescue Intervention (January 2016 report)
Stroke and Other Neurological Adverse Events
The most recent post-approval study results suggest that there is also a difference in clinical performance between the C2 Driver System and the CSS Console in terms of neurological adverse events.
The INTERMACS Neurological Adverse Event (AE) outcome is a composite of several separate adverse events including: transient ischemic attacks, confusion, ischemic/embolic stroke, hemorrhagic stroke, strokes from other causes, seizures, encephalopathy, and other events. The INTERMACS Neurological AE rates from the first three months after TAH-t implant were provided for patients initially supported by the C2 Driver System and for patients initially supported by the CSS Console (Table 3). The Neurological AE rate in the first three months post-implant is higher for patients initially supported with the C2 Driver System (31 percent) compared to patients initially supported with the CSS Console (16 percent; p =0.02).
These results are not adjusted for potential confounders, and they were not further stratified by pre-implant circulatory rescue intervention status. The Neurological AE rate will continue to be monitored, and additional analyses will be performed as appropriate in the future.
Table 3. All Patients (January 2016 report)
Data Limitations
Post-approval studies of the TAH-t and our investigation into these issues are ongoing. We do not know the root cause for these observed differences, and the existing data is limited. INTERMACS only captures information regarding the initial driver used to support TAH-t patients, and at this time, only unadjusted interim rates are available. Although we are concerned about the difference in outcomes between the C2 Driver System and the CSS Console, we recognize that the C2 Driver System may be the best option for circulatory support for some patients.
Freedom Driver System
In addition to the C2 Driver System and the CSS Console, a third pneumatic driver system, the SynCardia Freedom Driver System, is also available to power the SynCardia TAH-t. The Freedom Driver System is portable and can be used outside of the hospital, allowing some TAH-t patients to return home while on the device.
The FDA is aware of recent reports of serious, life-threatening TAH-t device malfunctions involving the Freedom Driver System. These reported malfunctions have included sudden cessation of TAH-t pumping without warning alarms or recognizable signs of impending malfunction (such as a change in sound during the Freedom Driver System’s operation). The Freedom Driver System was also the subject of a Class 1 Recall initiated on August 7, 2015, but these recent reports appear to be unrelated to the issues that prompted the recall last year.
The FDA is working with SynCardia and clinicians to fully assess reports of malfunction involving the Freedom Driver System. In light of these recent reports, the FDA advises that clinicians review the Operator Manual’s specific precautions regarding Freedom Driver System use outside of a hospital environment, and carefully consider individual patient circumstances when evaluating the Freedom Driver System as a treatment option.
RECOMMENDATIONS
The FDA has the following recommendations for health care providers:
- Carefully consider these mortality and neurological adverse event results, and device malfunction reports when making treatment decisions and device selection, and discuss the risks and benefits of these devices with your patients.
- Report any adverse events or suspected adverse events experienced with the SynCardia TAH-t Driver Systems (the C2 Driver, the CSS Console, or the Freedom Driver). Voluntary reports can be submitted through MedWatch, the FDA Safety Information and Adverse Event Reporting program. Device manufacturers and user facilities must comply with the applicable Medical Device Reporting (MDR) regulations. Health care personnel employed by facilities that are subject to FDA’s user facility reporting requirements should follow the reporting procedures established by their facilities. Prompt reporting of adverse events can help the FDA identify and better understand the risks associated with medical devices.
- Return all devices associated with, or suspected to be associated with, any adverse events to the manufacturer for evaluation to help them and FDA better understand the issue.
The FDA has the following recommendations for facilities that participate in INTERMACS:
- Continue to enter high-quality data for these devices into INTERMACS, since this data is used to understand individual patient events and factors contributing to patient outcomes.
FDA ACTIONS
The FDA continues to work with SynCardia and INTERMACS to better understand these observations in patients using the C2 and Freedom Driver Systems, and will provide updates and additional information on all Syncardia TAH-t Driver Systems as it becomes available.
CONTACT US
If you have questions about this communication, please contact the Division of Industry and Consumer Education (DICE) at [email protected], 800-638-2041 or 301-796-7100.
Sincerely,
/s/
William Maisel, MD, MPH
Deputy Center Director for Science
Center for Devices and Radiological Health
U.S. Food and Drug Administration