Atrial fibrillation (AF) is a prevalent cardiac arrhythmia affecting millions of individuals worldwide and posing significant challenges to healthcare systems. The growing body of research has uncovered sex-related differences in AF pathophysiology, including the role of fatty acid-binding protein 4 (FABP4) and leptin as potential biomarkers. FABP4 and leptin, key adipokines involved in cardiovascular health, have been linked to inflammation, oxidative stress, and endothelial dysfunction, all of which may contribute to AF development. These adipokines exhibit sex-specific differences in their concentrations, with females generally showing higher FABP4 levels and males displaying distinct leptin profiles. Furthermore, hormonal influences, particularly estrogen, and testosterone, play significant roles in shaping AF risk and atrial remodeling. Estrogen is associated with cardioprotective effects, while testosterone may exert proarrhythmic effects. Understanding these sex-specific mechanisms could lead to more tailored and effective clinical management of AF. The future of AF research holds promise for precision medicine, novel therapeutic targets, artificial intelligence integration, and personalized care approaches. Emphasizing patient-centered care, telemedicine, and multidisciplinary collaboration can further enhance AF management and improve patient outcomes. In conclusion, recognizing and addressing sex-related factors in AF pathophysiology offer opportunities for gender-responsive interventions and advancements in AF management. Implementing these insights may pave the way for targeted therapies and improved quality of life for individuals affected by AF.

Abstract: Differences in clinical manifestations between strains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported. This retrospective descriptive study compares the clinical and demographic characteristics of all confirmed coronavirus disease (COVID-19) cases admitted to the National Isolation Centre (NIC) in the first wave and at the beginning of the second wave of the pandemic in Brunei Darussalam. Methods: All COVID-19 cases admitted to the NIC between 9 March and 6 May 2020 (first wave) and 7–17 August 2021 (second wave) were included. Data were obtained from NIC databases and case characteristics compared using Student’s t-tests and chi-squared tests, as appropriate. Results: Cases from the first wave were significantly older than those from the second wave (mean 37.2 vs 29.7 years, P<0.001), and a higher proportion reported comorbidities (30.5% vs 20.3%, P=0.019). Cases from the second wave were more likely to be symptomatic at admission (77.7% vs 63.1%, P<0.001), with a higher proportion reporting cough, anosmia, sore throat and ageusia/dysgeusia; however, myalgia and nausea/vomiting were more common among symptomatic first wave cases (all P<0.05). There was no difference in the mean number of reported symptoms (2.6 vs 2.4, P=0.890). Discussion Our study showed clear differences in the profile of COVID-19 cases in Brunei Darussalam between the first and second waves, reflecting a shift in the predominating SARS-CoV-2 strain. Awareness of changes in COVID-19 disease manifestation can help guide adjustments to management policies such as duration of isolation, testing strategies, and criteria for admission and treatment.