Stroke Risk as a Function of Atrial Fibrillation Duration and CHA₂DS₂-VASc Score

Area of Science:

• Cardiology
• Electrophysiology
• Medical Informatics

Background:

• Atrial fibrillation (AF) duration is linked to stroke risk, but its interplay with CHA2DS2-VASc score in patients with cardiovascular implantable electronic devices (CIEDs) is unclear.
• Understanding this interaction is crucial for refining stroke risk stratification and therapeutic strategies.

Purpose of the Study:

• To investigate the combined impact of AF duration and CHA2DS2-VASc score on stroke and systemic embolism (SSE) rates in patients with CIEDs.
• To identify specific thresholds of AF burden and CHA2DS2-VASc score that indicate increased SSE risk.

Main Methods:

• Utilized deidentified electronic health record and Medtronic CareLink data from 21,768 patients with CIEDs (2007-2017).
• Assessed CHA2DS2-VASc score and categorized AF duration (none, 6 minutes-23.5 hours, >23.5 hours) prior to an index date.
• Calculated annualized SSE rates post-index date for non-anticoagulated patients.

Main Results:

• Both increasing AF duration and CHA2DS2-VASc score were significantly associated with higher SSE risk (P<0.001).
• SSE rates remained low for CHA2DS2-VASc scores 0-1, irrespective of AF duration.
• Actionable stroke risk (>1%/year) was observed in patients with CHA2DS2-VASc score ≥2 and significant AF burden, or CHA2DS2-VASc score ≥5 even with minimal AF.

Conclusions:

• A significant interaction exists between AF duration and CHA2DS2-VASc score for SSE risk stratification in CIED patients.
• This combined assessment offers a more nuanced approach to identifying high-risk individuals.
• Findings may inform personalized anticoagulation therapy decisions to mitigate stroke risk.