Figure 2 illustrates the Kaplan–Meier curves estimated from the onset of index stroke to AF detection. AF detection rate was 13.3%/year, 12.8%/year, and 53.7%/year in the low-, mid-, and high-BNP groups, respectively (log-rank trend p < 0.01). Compared to the low-BNP group, the adjusted hazard ratios for AF detection in the mid-BNP and high-BNP groups were 0.91 [95% confidence interval (CI) 0.46–1.78, p = 0.77] and 2.17 (95% CI 1.14–4.13, p = 0.02), respectively (Table 2). Here, NPPB is linked to atrial fibrillation.