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  1. Letters to Health Care Providers

UPDATE on SynCardia Systems - TAH-t Companion 2 Driver System (C2) and Freedom Driver System - Letter to Health Care Providers (Unpublished)

September 25, 2017

Update Regarding Mortality and Neurological Adverse Events

The FDA is issuing this update to our October 2016 letter to inform the health care community of the most recent, interim results from the ongoing SynCardia TAH-t post-approval study that is looking at mortality and neurological adverse events.

These interim results, which are available on the Post-Approval Studies webpage, continue to reflect a higher three-month mortality rate for the subgroup of patients requiring pre-implant circulatory rescue interventions when using the C2 Driver System compared to those using the CSS Console. The mortality rates for patients who did not require pre-implant circulatory rescue interventions continued to be similar for the C2 Driver System compared to the CSS Console.

In addition, interim results continue to show a higher neurological adverse event rate in the first three months post-implant for patients initially supported with the C2 Driver System compared to patients initially supported with the CSS Console. This rate is attributed mostly to the difference in the rate of cerebrovascular accidents between the two groups. The neurological adverse event rate is a composite outcome of several separate adverse events including: cerebrovascular accidents (transient ischemic attacks, ischemic/embolic stroke, and hemorrhagic stroke), strokes from other causes, confusion, seizures, encephalopathy, and other events.

FDA’s evaluation and the TAH-t post approval study are ongoing. As the TAH-t functions as a bridge to a heart transplant in a small population of heart failure patients with severe bi-ventricular failure, we recognize that physicians may determine that the C2 Driver System may be the best and possibly only option for circulatory support. We expect to receive final post-approval study results at the end of 2017 for FDA review.

We also now have more information to share regarding reports of Freedom Driver malfunctions, including cessation of the TAH-t’s pumping without warning alarms or recognizable signs of impending malfunction. The sudden loss of circulatory support may lead to serious adverse health consequences or death. These malfunctions appear to be mainly the result of dropping or rough handling the Freedom Driver, though FDA continues to work with SynCardia to fully assess these events and their possible root causes.


The FDA strongly recommends the following:

  • Health care providers, patients, and caregivers should review the recently updated Freedom Driver Operator’s Manual for specific precautions regarding Freedom Driver System use outside of a hospital environment—particularly instructions concerning Freedom Driver exchange after a drop or rough handling.
  • Health care providers should discuss the risks and benefits of the Freedom Driver with their patients, and train new and existing patients and caregivers on the recently updated Freedom Driver Operator’s Manual—specifically focusing on the warnings and precautions with regard to drops or rough handling and the patient’s actions should one of these activities occur.
  • Health care providers should carefully consider these mortality and neurological adverse event results from the TAH-t post-approval study when making treatment decisions and device selection, and discuss the risks and benefits of the C2 Driver System and the CSS Console with patients.
  • Health care providers should report any adverse events related to the SynCardia TAH-t and all Driver Systems (the C2 Driver, the CSS Console, and 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 toFDA'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.
  • Health care providers should 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.

FDA will continue to keep the public informed as significant new information becomes available.

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