The Guardian was approved by the FDA in 2018 and launched in a controlled manner in June, 2021

The ALERTS Study

The ALERTS study design evaluated the safety and efficacy of the Guardian System. The ALERTS study was a prospective, randomized multi-center study with FDA approval for 100 centers and 1020 subjects at high-risk of having recurrent acute coronary syndrome (ACS) event.

The Guardian System was developed to provide patient alerting for onset of ACS events, and detection of heart rate and rhythm abnormalities.

Detection of Coronary Artery Occlusion

Review of clinical studies evaluating the design, safety and efficacy of The Guardian System. Kazmi, et al., (2020). Med Devices (Auckl). Jan 7;13:1-12

Early Recognition and Treatment of STEMI

Implantable Cardiac Alert System for Early Recognition of ST-Segment Elevation Myocardial Infarction. Gibson CM, Holmes D, Mikdadi G, et al., (2019). Journal of the American College of Cardiology, 73(15), 1919–1927.

Decreased Pre-Hospital Delay

Implanted Monitor Alerting to Reduce Treatment Delay in Patients with Acute Coronary Syndrome Events. Holmes DR Jr, Krucoff MW, Mullin C, et al., (2019). Journal of the American College of Cardiology, 74(16), 2047–2055.


Rationale and design of the AngeLmed for Early Recognition and Treatment of STEMI trial: A randomized, prospective clinical investigation. Gibson MC, Krucoff M, Fischell D, et al., (2014). American Heart Journal, 168(2), 168–174.

Indications for Use

The Guardian is an implantable cardiac monitor with patient alerting capability and an additional external alarm device. The Guardian System is indicated for use in patients who have had prior acute coronary syndrome (ACS) events and who remain at high risk for recurrent ACS events.

The Guardian System is indicated as an adjunct to patient recognized symptoms. The Guardian System detects potential ongoing ACS events, characterized by sustained ST segment changes, and alerts the patient to seek medical attention for those potential ACS events.

A Guardian System alert is a more accurate predictor of ACS events when compared to patient recognized symptoms alone and demonstrates a reduced rate over time of patient presentations without ACS events (false positives) when compared to patient recognized symptoms alone.

In the absence of symptoms, the Guardian System may identify asymptomatic ACS events and prompt the patient to seek medical attention.

The Guardian System is contraindicated in:

  1. 1

    Patients with cognitive impairment that would prevent recognition of alarms

  2. 2

    Patients who cannot feel the vibration from the IMD

  3. 3

    Patients with implanted pacemaker, implantable cardioverter defibrillator or cardiac resynchronization therapy devices

  4. 4

    Patients where a pacemaker lead cannot be placed safely