Associations Between Changes in Maximum Daily Atrial Fibrillation Duration, Ischemic Stroke, and Mortality

Area of Science:

• Cardiology
• Medical Devices
• Public Health

Background:

• Atrial fibrillation (AF) outcomes are significantly influenced by continuous measures of AF burden.
• Understanding AF burden dynamics is critical for managing patient risk.

Purpose of the Study:

• To evaluate the association between changes in maximum daily AF duration (MDAFD) and the risk of stroke or mortality.
• To investigate these associations in patients with cardiac implantable electronic devices (CIEDs) not receiving oral anticoagulation.

Main Methods:

• Utilized Optum deidentified electronic health record data linked with the Medtronic CareLink heart rhythm database (2007-2021).
• Included patients with CIEDs and recorded health care activity, excluding those on oral anticoagulation.
• Assessed MDAFD at baseline (30 days post-implant) and prior to censoring or event, adjusting HRs for CHA₂DS₂-VASc components, baseline MDAFD, and chronic kidney disease.

Main Results:

• Analyzed 26,400 patients; 9.6% had AF at baseline.
• Increased MDAFD during follow-up was associated with a higher adjusted rate of stroke and mortality (HR: 1.80).
• Decreased MDAFD showed no significant association with the combined endpoint (HR: 0.82), but subgroup analysis revealed risk reductions in specific baseline MDAFD categories.

Conclusions:

• In CIED patients not on oral anticoagulation, an increase in MDAFD is linked to elevated stroke and mortality rates.
• AF burden and its associated risks are dynamic and can change over time, highlighting the need for ongoing monitoring.