High pro-BNP levels predict the occurrence of atrial fibrillation after cryptogenic stroke

Objective: Antiplatelets are recommended for secondary prevention in patients with cryptogenic stroke; however, some patients may present with a cardioembolic source that has not been detected, which may modify the treatment. Because high pro-brain natriuretic peptide (BNP) levels are associated with cardioembolic stroke, our objective was to determine whether proBNP levels in the acute phase of stroke predict the development of atrial fibrillation (AF) in patients with cryptogenic stroke. Methods: A prospective study including patients with cryptogenic stroke was conducted. Demographic data, medical history, and stroke characteristics were assessed at admission. A blood sample was obtained within the first 24 hours from stroke onset to determine pro-BNP levels. Patients were followed by a neurologist at 3 and 6 months and later by a primary care physician for 2 years to evaluate the development of AF. Results: One thousand fifty patients with ischemic stroke were evaluated. Three hundred seventytwo patients (35%) had cryptogenic stroke. One hundred eight patients were excluded from the study, so 264 patients were valid for the analysis. AF was detected in 15 patients (5.6%) during the follow-up. Patients who developed AF were older, had hypertension more frequently, and showed higher levels of pro-BNP. In the logistic regression model, we found that pro-BNP >= 360 pg/mL was the only variable independently associated with the risk of developing AF (odds ratio 5.70, 95% confidence interval 1.11-29.29, p = 0.037). Conclusions: Pro-BNP >= 360 pg/mL increases by 5-fold the possibility of detecting AF during follow-up in patients with cryptogenic stroke.