The rapid transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the coronavirus disease 2019 (COVID-19) pandemic. SARS-CoV-2 has been characterized to be highly virulent and transmissible, causing a wide range of infections, ranging from mild to severe.
Since the onset of the pandemic, scientists have worked extensively hard to understand various aspects of the virus, its mode of infection, the underlying mechanism, and how it affects various age groups and individuals with comorbidities.
According to some reports, Italy was one of the most affected countries during the first wave of SARS-CoV-2 infection. Scientists believe that atrial fibrillation (AF) may complicate the clinical outcome of COVID-19 disease, especially, for hospitalized patients. AF is an irregular and extremely rapid heart rhythm (arrhythmia) that can cause blood clots in the heart. AF patients are at a high risk of heart failure, stroke, and other cardiac complications.
Researchers have stated that pre-existing AF could affect the clinical outcome of severely infected hospitalized COVID-19 patients because it might enhance the overall body inflammation. Additionally, AF decreases the ability of an individual to compensate for the hemodynamic alterations of acute SARS-CoV-2 illness. Scientists have stated that very scarce evidence is available on the prognosis of hospitalized COVID-19 patients with a history of AF.
Although previous studies have indicated a strong association between cardiovascular diseases and COVID-19, very limited data are available about how different forms of AF affect the clinical outcomes of COVID-19 disease.
A new study
Addressing the aforementioned research gap, scientists have evaluated if AF could be regarded as a comorbidity. They further determined the type of pre-existing AF that enhances the risk of developing severe forms of SARS-CoV-2 infection or even death. This study is available in Medicina.
In this study, scientists performed an observational retrospective analysis of COVID-19 patients hospitalized in nine Italian Hospitals, between 1st March and 30th April 2020. They obtained reports of the clinical outcomes, pharmacological therapy provided, and whether these patients had a history of AF and its type (paroxysmal, persistent, or permanent). The cohort was divided into two groups based on the pre-existence of AF as comorbidity - one group was without AF history and the other had a history of AF.
Further, the group containing individuals with a history of AF was subdivided based on the types, i.e., permanent AF history groups and non-permanent AF history groups. In this study, scientists diagnosed AF using 12-lead electrocardiographic (ECG) or continuous ambulatory ECG monitoring.
The current study revealed that 25% of patients hospitalized due to COVID-19 infection had a history of AF. This result confirms that AF is a frequent comorbidity associated with SARS-CoV-2 infection. Although previous studies have shown that a history of AF is strongly linked with acute respiratory distress syndrome (ARDS), this study revealed that it does not affect in-hospital mortality. A prior study conducted in Northern Ireland reported that 75% of elderly patients hospitalized due to COVID-19 had a history of AF. According to the data provided by the COVID-19 Task Force of the Italian National Institute of Health, AF was present in 24.5% of 355 non-surviving COVID-19 patients. Recently, the New York State Department of Health reported that AF is the seventh among COVID-19 comorbidities.
The authors of this study reported that AF affects the clinical outcome of COVID-19 patients, by enhancing the possibility of ARDS. They emphasized that AF must be considered among the cardiovascular comorbidities that cause rapid deterioration of the respiratory disease. Previous studies have hypothesized that AF could be the arrhythmic marker of underlying inflammatory actions, which initially favors and later amplifies COVID-19 infection and finally, leads to worse respiratory outcomes.
The difference in the findings of the current study with a previous study on the risk of in-hospital mortality might be due to a divergent study cohort that constituted a varied prevalence of hospitalized patients with AF.
The present study concluded that the clinical outcome of hospitalized COVID-19 patients was not affected by the type of pre-existing AF (permanent or non-permanent).
The findings of the current study are in line with previous studies on the occurrence of thromboembolic events and pulmonary embolism.
Two of the limitations of this study are its observational retrospective design and the heterogeneity in the clinical presentation of SARS-CoV-2 infection. Additionally, due to the lack of computed tomography imaging data, researchers determined the severity of SARS-CoV-2 infection based on the presence of severe ARDS during hospitalization. A further limitation of this study is its small sample size.
This study revealed that pre-existing AF is a frequent comorbidity in hospitalized COVID-19 patients, which has been independently associated with ARDS, but not with in-hospital mortality. The authors recommended careful clinical monitoring of COVID-19 hospitalized patients with AF, for early detection of those who are at a higher risk of developing ARDS.