Timing of stroke risk reassessment in atrial fibrillation patients with CHA2DS2-VA score of 0 or 1: the Norwegian AFNOR study.

BACKGROUND AND AIMS

Stroke risk in atrial fibrillation (AF) patients increases over time, but the optimal reassessment interval remains unclear. This study evaluated changes in the CHA2DS2-VA score in AF patients with low (score 0) or intermediate (score 1) stroke risk and explored appropriate reassessment intervals.

METHODS

Using Norwegian national registries (2011-2018), 40,782 individuals with incident AF aged ≥18 years and a low or intermediate CHA2DS2-VA score were identified. Patients were followed from first AF diagnosis until an increase in the CHA2DS2-VA score, and the proportion with increased score was assessed across age groups. The number needed to reassess to detect one new CHA2DS2-VA risk factor was calculated at different time intervals after AF diagnosis.

RESULTS

The CHA2DS2-VA score increased in 50% of patients after a median follow-up of 1.7 years. The proportion of patients with increased CHA2DS2-VA score was 19% at 6 months, 25% at 1 year, and 40% at 3 years after AF diagnosis. At 1 year, the proportion of patients with a new risk factor was lower in those aged 18-44 years (8%) and 45-54 years (14%) compared to those aged >55 years (30%), with the number needed to reassess at 1 year being 12, 7, and 3 patients, respectively.

CONCLUSION

New risk factors emerged in half of AF patients within 1.7 years. Age-specific differences underscore the need for tailored reassessment, suggesting a shorter interval of 6 months for patients ≥55 years and 1 year for those <55 years, and routinely at age 65 and 75 years.