CHADSVASc score as a predictor of atrial fibrillation after cryptogenic stroke: implications for early anticoagulation

Background

Atrial fibrillation (AF) is a frequent but often undiagnosed cause of cryptogenic stroke. Continuous rhythm monitoring with implantable loop recorders (ILRs) has improved AF detection rates, but selecting patients most likely to develop AF remains a clinical challenge. The CHA2DS2-VASc (CHADVA) score, traditionally used to estimate thromboembolic risk, may also reflect underlying atrial vulnerability and predict new-onset AF after stroke [1–5].

Methods

We analyzed 148 consecutive patients with cryptogenic stroke who underwent ILR implantation. The CHADVA score was calculated at baseline, and the occurrence of AF during follow-up was recorded. Between-group comparisons were performed using t-tests and χ²/Fisher’s exact tests. Logistic regression was used to assess the predictive value of CHADVA for post-stroke AF.

Results

AF was detected in 24.3% of patients. Mean CHADVA score was 5.28 ± 1.23 in patients with AF and 4.53 ± 1.36 in those without (p = 0.003). Using a cut-off of 4 points, the incidence of AF was 32.9% for CHADVA > 4 and 14.5% for CHADVA ≤ 4 (p = 0.012), yielding an odds ratio (OR) = 2.89 [95% CI 1.27–6.60].

When modeled as a continuous variable, CHADVA remained an independent predictor of post-stroke AF (OR = 1.56 [95% CI 1.16–2.09], p < 0.01). This means that each 1-point increase in CHADVA raises the odds of developing AF by 56%, with a progressive, nearly linear increase in AF probability with rising CHADVA scores: from approximately 13% at CHADVA = 3 to >55% at CHADVA = 8. This confirms that each incremental point in CHADVA substantially increases the likelihood of post-stroke AF.

Conclusions

A higher CHA2DS2-VASc score is strongly associated with an increased risk of atrial fibrillation after cryptogenic stroke. A threshold of > 4 identifies patients with almost threefold greater odds of AF detection.

Beyond its established role in thromboembolic risk estimation, CHADVA may serve as a dual-purpose tool to stratify patients for prolonged rhythm monitoring and to consider early anticoagulation in those at highest risk, potentially preventing recurrent embolic events.

Prospective, randomized studies are needed to test whether a CHADVA-guided anticoagulant strategy can reduce secondary stroke rates in this population.