ACE2 and atrial fibrillation: SARS-CoV-2 has been found in thrombi of brain arteries from acute ischemic stroke patients, who also showed systemic high neutrophil-to-lymphocyte ratio as well as higher angiotensin-converting enzyme 2 (ACE2) expression (32), and COVID-19 has also been implicated in causing acute cardiac injury, arrhythmias, and atrial fibrillation, which are commonly found in COVID-19 patients, with increased risk of thromboembolism and subsequent stroke (25, 28).