Merlin Programmer Software and Remote Monitoring Application when used with pacemakers in the Accent/Anthem and Endurity/Assurity/Allure family | Heart Rhythm Society

Merlin Programmer Software and Remote Monitoring Application when used with pacemakers in the Accent/Anthem and Endurity/Assurity/Allure family

June 21, 2022 — Abbott has identified the potential for programmer software (MerlinTM PCS) and remote monitoring software applications ( to display overestimated predicted battery longevity for certain pacemakers. Pacemaker/battery functionality, therapy delivery, and longevity remain normal and within specifications. Voltage measurements and ERI (elective replacement indicator), which are based on direct voltage measurement, remain accurate. This advisory does not apply to battery estimates for other devices (such as ICDs).

Safety Alerts
U.S. Food and Drug Administration (FDA)


Publication Date: June 21, 2022

At interrogation, the programmer software uses an algorithm to estimate the remaining device battery longevity based on battery voltage and projected battery performance. The current algorithm overestimates battery longevity, particularly during mid- to late-stage device life. Nearing ERI, the longevity estimate improves, reducing overestimation. However, as this occurs, users may observe a larger than expected drop in the remaining battery longevity estimate compared to the prior estimate, which may cause the appearance of a rapid change in battery performance.  
Worldwide as of May 2022, there have been 585 complaints reported for this issue, and 30 devices were prematurely explanted prior to ERI (as a precaution). No patient harm or adverse events were reported as a result.


Abbott has developed software updates for the Merlin programmer and remote monitoring application, which correct this issue. was updated globally on June 18, 2022, whereas programmers will require manual updating individually, and therefore, timing will vary by country and geographic region. In the U.S., Abbott representatives will update programmers starting in July 2022.
Upon programmer software / remote monitoring software update, the improved longevity estimate will be displayed at the patient’s next interrogation. A difference in longevity estimates between programmer and remote monitoring ( may be observed if the programmer has not yet been updated with the new software ( estimate is more accurate in this case).

Abbott Recommendations

Abbott provides the following guidance:

  1. Prophylactic device replacement is not recommended, as device functionality, actual longevity, and ERI indicator are not impacted (device functionality remains normal and within specifications).
  2. Routine follow-up should remain per local standard of care and clinical protocol, and ERI should continue to serve as an indicator of the need for device replacement scheduling. 
  3. Please direct any questions about device longevity to Abbott Technical Support at 1-800-722-3774 (U.S.).

HRS Recommendations 

HRS strongly encourages its members to read the U.S. Abbott Safety notification or International Abbott Safety notification.

Reporting Adverse Reactions or Quality Problems 

Adverse reactions or quality problems experienced with the use of this product should be reported to Abbott and to the FDA MedWatch Safety Information and Adverse Event Reporting Program either online, by regular mail, or by fax.

For additional questions, contact your local Abbott Representative or Abbott Technical Services at 1-800-722-3774. 

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