Accurate etiology diagnosis in patients with stroke and atrial fibrillation: A role for brain natriuretic peptide.

Background: Atrial fibrillation (AF) is the leading cause of cardioembolic stroke (CES), and patients with stroke and AF are frequently assumed to have CES. However, strokes presumably due to atherosclerotic pathophysiologies in large or small vessels can also occur in patients with AF. The aims of the present study were to clarify the prevalence of and factors related to a non-cardioembolic etiology in acute stroke patients with AF.

Methods: From March 2011 through May 2017, consecutive acute ischemic stroke patients with AF were retrospectively recruited. The concomitant presence of non-cardioembolic features (small vessel occlusion [SVO] or large artery atherosclerosis [LAA]) on imaging was evaluated. The frequency of and factors associated with co-existing SVO/LAA features were assessed.

Results: A total of 560 consecutive patients with AF and acute stroke (237 women; median age 78 [IQR 71-85] years; NIHSS score 9 [3-20]) were enrolled. Of these, 42 (7.5%) had co-existing SVO/LAA features. Multivariable logistic regression analysis showed that the brain natriuretic peptide level (BNP, OR 0.78, p = .030 per 100 pg/mL increase) was independently and negatively associated with co-existing SVO/LAA features and receiver operating characteristic curve analysis revealed the practical cut-off BNP value was 130 pg/mL (sensitivity 54% and specificity 68%).

Conclusion: SVO/LAA features were found in 7.5% of acute stroke patients with AF. A relatively low BNP level on admission was independently associated with co-existing SVO/LAA features. Thorough examination for a more appropriate etiology may be particularly necessary in acute stroke patients with AF and a relatively low BNP level.