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

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. [Figure: see text] [Figure: see text]