An FDA advisory panel recommended against the approval of the AngelMed Guardian system, an implantable cardiac monitor, designed to detect rapid changes in the heart’s electrical signal caused by a coronary artery occlusion.
The Circulatory System Devices panel met on March 16. Each of the 12 members voted against the AngelMed Guardian System when asked if there was “reasonable assurance” that the device was effective in patients with prior acute coronary syndrome events to ST segment changes indicating acute coronary occlusion. They also all voted against the benefits of the device outweighing the risks in the same patient population.
AngelMed Systems, the device manufacturer, submitted data from ALERTS, a randomized, prospective study that enrolled 907 high-risk patients who had a previous MI or acute coronary syndrome event. The patients were implanted with the system and were randomized to have the device’s alerting feature turned on or off for six months.
“The panel was extremely troubled by the effectiveness results collected in the ALERTS Trial,” the members wrote. “The results from the trial were: inconclusive between the treatment and control groups; captured very few cardiac/unexplained deaths; had many new Q waves without an alarm; and many alarm events without a new Q wave. Further, when looking at the time-to-door component of the primary endpoint the Panel had a difficult time reconciling how events in the control group caught only in the longest look-back windows could have any connection between the ST deviation detection and the confirmatory testing. Finally, there was concern regarding the interpretability of the positive predictive value (PPV) calculation given the missing data and definition of clinically meaningful events. The false positives and false negatives identified in the study both raised concern.”
The panel also had concerns with the device’s safety: eight of the members voted against its safety, while the remaining four voted in favor of the safety. A few panelists mentioned the risks and implications of an implanted transvenous system and noted that device-related complications would increase over time.
The system includes an implantable medical device implanted in a left pectoral subcutaneous pocket; an external telemetry device given to each patient; and a specially configured portable computer used to configure the implantable medical device and retrieve and store patient data.