Findings from a study published in HeartRhythm showed that atrial fibrillation (AF) occurred in 17.6% of patients hospitalised with coronavirus disease 2019 (COVID-19) and that AF, particularly new-onset AF, was an independent predictor of in-hospital mortality.
The study, conducted at 13 hospitals in the Northwell Health system, included 9,564 patients admitted between March 1 and April 27, 2020 with a positive COVID-19 polymerase chain reaction test. Patients data were extracted from the common medical record system of the hospitals. The average age of the cohort was 64.8 years and more than half (58.9%) were male.
Patients were followed through May 31, 2020. The primary outcome of the study was in-hospital mortality.
Of the patients, 1,687 (17.6%) experienced AF during the course of hospitalisation, whereby 1,109 patients (65.7%) had new onset AF. Comorbidities that were more frequent in patients with AF included a history of hypertension, coronary artery disease, congestive heart failure, peripheral vascular disease, renal disease, chronic obstructive pulmonary disease, cancer and diabetes.
Propensity score matching (PSM) 1,238 pairs of patients with AF and without AF showed higher in-hospital mortality in the AF group (54.3% vs 37.2%, P< 0.0001). The relative risk of in-hospital mortality among those with AF compared to those without AF was 1.46 (95% confidence interval [CI], 1.34-1.59).
Within the AF group, PSM of 500 pairs demonstrated higher in-hospital mortality in patients with new onset AF compared with patients with a past history of AF (55.2% vs 46.8%, P = 0.009) for a relative risk of in-hospital mortality of 1.18 (95% CI, 1.04-1.33).
Meanwhile, when 1,107 patients with new onset AF were matched and compared to patients without AF, researchers found a significantly higher in-hospital mortality in the new onset AF group (56.1% vs 36.0%), yielding a risk ratio of 1.56 (95% CI, 1.42-1.71, P <0.0001).
On the other hand, the presence of cardiac disease was not associated with a higher risk of in-hospital mortality among patients with AF (P = 0.1).
“Recently, it has been suggested that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may directly contribute to the pathogenesis of AF through attaching to pericytes, cells responsible for microvascular integrity of cardiac tissue,” wrote Stavros E Mountantonakis, MD, Northwell Health, New York, and colleagues. “This results in the release of a number of growth factors, causing cardiac tissue inflammation and altering atrial cellular electrophysiology. Similarly, dysregulation of cellular angiotensin-converting enzyme 2 receptors by the SARS-CoV-2 results in the release of angiotensin II further contributing to AF.”
The authors noted that the strong association between AF and COVID-19 mortality was most likely driven by the new AF cases, with more than 50% of patients with newly diagnosed AF dying, suggesting a strong association between the development of AF and in-hospital mortality. “This study highlights the importance of utilising AF as a clinical and non-invasive marker of in-hospital mortality in hospitalised COVID-19 patients,” the authors added.