Abstract Body: Background:
In patients with ischemic stroke who receive insertable cardiac monitors, the CRYSTAL-AF and STROKE-AF randomized trials showed similar (~12%) AF detection rates at one year among patients with cryptogenic stroke and stroke from large vessel disease and small vessel disease, respectively. This finding may suggest that AF detected on an insertable cardiac monitor in cryptogenic stroke is often not pathogenic. In this study, we aim to compare AF detection rates on ZIOPATCH in ESUS vs. non-cardioembolic ischemic stroke.

Methods:
From a comprehensive stroke center registry, we identified patients with a diagnosis of ischemic stroke who underwent a ZIOPATCH to look for AF. The primary predictor was stroke subtype (ESUS vs. non-cardioembolic). Non-cardioembolic stroke was defined as stroke from large artery atherosclerosis, small vessel disease, or other known mechanism. ESUS was defined using the ESUS consensus criteria. The study outcome was AF detected on ZIOPATCH. We compared baseline characteristics and risk factors between patients with vs. without AF detected. Univariate and multivariate regression models were used to determine odds ratios (OR).

Results:
We identified 478 patients who had a ZIOPATCH placed; 410 had the ZIOPATCH completed (217 ESUS, 71 small vessel disease, 100 large vessel disease, and 22 had another defined mechanism). The mean age was 69 years and 51% were men. The mean duration of ZIOPATCH monitoring was 12 days and 17 (4.1%) had AF. Patients with AF were more likely to be older (82 years vs. 68 years, p<0.001), female (88% vs. 48%, p<0.001), and have ESUS (88% vs. 52%, p = 0.013). In adjusted models, ESUS patients were more likely to have AF detected on ZIOPATCH (adjusted OR 3.70, 95% CI 1.01-13.5, p = 0.048). Notably, only 29% of patients with ESUS and negative ZIOPATCH underwent and insertable cardiac monitor.

Conclusions:
There is increased prevenance of AF on ZIOPATCH in patients with ESUS compared to non-cardioembolic stroke. This suggests that AF detected after the stroke on ZIOPATCH may present a pathogenic entity.