Atrial fibrillation and in-hospital mortality in Covid-19 patients

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Wellcome/EPSRC Centre for Medical Engineering Background Although primarily considered a respiratory virus, cardiovascular manifestations have been reported in patients with Covid-19 infection. Atrial fibrillation has been observed as the most common arrhythmia with the prevalence rate reportedly as high as 16.5%(1). Purpose The aim of the study was to establish the incidence of atrial fibrillation in patients hospitalised with Covid-19 and evaluate the relationship between patient characteristics and disease severity with new-onset atrial fibrillation in patients with Covid-19. Methods A single centre, retrospective study of 1241 patients with a confirmed PCR diagnosis of Covid-19 admitted during the 1st wave of the pandemic (1st March to 31st September 2020). Patient demographic data, medical history and clinical outcome data were manually collected. Results The study population comprised of 1241 patients hospitalised with Covid-19. Of these, 94 (7.6%) patients were known to have pre-existing atrial fibrillation. In an unadjusted analysis, in-hospital mortality was twice as likely in patients with pre-existing atrial fibrillation compared to patients with no history of atrial fibrillation (odds ratio (OR): 2.18; 95% CI 1.29-3.59, p=0.002). However, after multi-variable matching for age, sex and CHA2DS2VASc score there was no significant difference between groups (OR: 1.13, 95% CI 0.57-2.21, p=0.732). During their admission, 42 (3.4%) patients developed new-onset atrial fibrillation. New-onset atrial fibrillation was associated with an increased risk of mechanical­­­ ventilation (OR: 4.59, 95% CI 2.34-9.06, p<0.005), intensive care admission (OR: 7.19, 95% CI 3.52-15.61, p<0.005) and in-hospital mortality (OR: 3.58; 95% CI 1.78-7.06, p<0.005). Statistical significance remained after matched analysis (mechanical ventilation OR: 14.00, 95% CI 1.84-106.5, p=0.01; intensive care admission OR: 18, 95% CI 2.40-134.83, p<0.005, in-hospital mortality OR: 2.80, 95% CI 1.01-7.77, p=0.048). New-onset atrial fibrillation was associated with older age (p<0.005), higher CHA2DS2VASc score (p<0.005), elevated white cell count (p=0.046), neutrophil count (p=0.010), C-reactive protein ( p<0.005), ferritin (p=0.020), lower albumin (p<0.005) and eGFR (p=0.013) at the time of hospital admission. No association was found with gender (p=0.683) or race (p=0.080). Conclusion New-onset atrial fibrillation during admission with Covid-19 is associated with both co-morbidity status and markers of disease severity at the time of hospital admission. New-onset atrial fibrillation is associated with elevated in-hospital mortality compared with patients with either pre-existing or no history of atrial fibrillation.