This study is aimed to depict the epidemiological trend, aetiologies, clinical characteristics, treatment options of IS-NOAC in face of the rapidly increasing NOAC usage. Knowledge on this ischaemic stroke entity will define clinical characteristics, identify preventable causes and inform resource allocation on the evaluation modalities, reperfusion strategies and forecast future burden of IS-NOAC.

Data will be retrieved from the stroke registry of Prince of Wales Hospital which recorded all in- and out-patients with stroke or transient ischaemic attack (TIA). All consecutive adult patients with known AF who developed ischaemic stroke or TIA in 2010, 2012, 2014, 2016 and 2018 (i.e. 5 full yearly time-points) and categorize the patients according to their anticoagulation status (elaborated below) with the inclusion and exclusion criteria stated will be recruited.

All demographic data, blood results, imaging and assessment data will be retrieved from electronic patient record (CMS system) and stroke registry. All-cause mortality at 1 year will be verified via CMS system too.

Inclusion Criteria:

1. Patients who were ethnic Chinese
2. Patients with known AF
3. Patient who suffered from ischaemic stroke

Exclusion Criteria:

1. Patient who are non-ethnic Chinese
2. Patient who suffered from haemorrhagic stroke

Patients with known AF who developed ischaemic stroke or TIA and admitted in the Prince of Wales Hospital in years 2010, 2012, 2014, 2016 and 2018 will be recruited into this study