Uncontrolled Asthma Associated with Atrial Fibrillation Risks

Aivaras Cepelis, BSc, MHS

A new study has found that asthma, particularly if it is uncontrolled, is associated with an increased risk of atrial fibrillation (AF).

The new analysis supplements previous studies, which have reported high levels of systemic inflammation biomarkers in adult patients with both AF and uncontrolled asthma. It has been shown in clinical settings that short-acting and long-acting beta-2 agonists, the most commonly prescribed asthma medication, can affect heart rate and increase risk for heart arrhythmias.

“Asthma medication is the first line of approach for asthma control and has been shown to be an effective treatment of asthma symptoms,” lead researcher Aivaras Cepelis, BSc, MHS, Norwegian University of Science and Technology told MD Magazine®. “This is the first study to look at an association between asthma control and atrial fibrillation.”

Researchers analyzed data from the Nord-Trøndelag Health (HUNT) Study, Norway’s largest population health study that originally began in 1984. They utilized the data of a total of 78,964 adults, aged 20 and older, who had answered positively to at least 1 question on asthma, asthma symptoms, and asthma medication use and did not have a diagnosis of AF at baseline.

Those who had symptoms indicating chronic obstructive pulmonary disorder (COPD), missing information on asthma baseline, and reported using asthma-associated medication and/or had asthma symptoms at baseline were excluded. The final number of participants in the study was 54,567.

Self-reported asthma was divided into 3 groups: those who ever had asthma, previous doctor-diagnosis of asthma, and active asthma. Symptom control was defined as controlled, partly controlled, and uncontrolled, in compliance with guidelines set by the Global Initiative for Asthma.

Results showed that participants with doctor-diagnosed asthma had a 38% increased risk of developing AF (adjusted mean ratio, 1.38; 95% CI; 1.18 - 1.61) compared to those without asthma. In addition, there was a dose-response association between levels of asthma control and AF risk, with the highest risk in those with uncontrolled asthma (adjusted hazard ratio, 1.74; 95% CI; 1.26 - 2.42]; P < 0.001).

Cepelis theorizes that there is a complex interplay between uncontrolled asthma symptoms, medication use (particularly the beta-2 agonists), and physical changes (inflammation and dysfunctional of autonomic nervous system) that all play a role in the association.

“Given the high prevalence of asthma, clinicians should closely examine AF risk factors in this patient group,” Cepalis said. “We need further investigation into the underlying mechanisms, including asthma medication use and inflammation, to clarify the causal pathways between asthma, asthma control and atrial fibrillation.”

The study, "Associations of Asthma and Asthma Control With Atrial Fibrillation Risk," was published online in JAMA Cardiology last week.

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