Atrial Fibrillation and Arrhythmias Common in Cardiac Sarcoidosis

Patients with cardiac sarcoidosis (CS) have a high burden of atrial fibrillation (AF) and related arrhythmias, according to a study in the International Journal of Cardiology.

The findings are based on a systematic review and meta-analysis that evaluated the epidemiology of AF in patients with CS.

Researchers performed a literature search in the Web of Science, Scopus, and PubMed/Medline databases from inception to April 26, 2023. They estimated the prevalence and incidence of AF in patients with CS with use of an inverse-variance weighted random-effects meta-analysis.

Overall, 16 studies and 1523 participants with an established diagnosis of CS were included. The studies were published from 2012 to 2022, and 43.8% were conducted in the United States. Participants had a mean age of 55.6±10.7 years, and 43% were men.

The prevalence of AF was assessed in 8 studies with 978 participants, with a pooled rate of 23% (95% CI, 13%-34%). Regarding AF subtypes based on 5 studies, paroxysmal AF was the most common with a prevalence of 83% (95% CI, 77%-90%), followed by persistent AF with a prevalence of 17% (95% CI, 10%-23%).

Based on 9 studies with 545 patients in which incidence rates could be inferred, the overall pooled estimate for AF incidence was 10.6% (95% CI, 4.9%-17.8%). The pooled estimate for AF incidence in patients with less than 2-year follow-up was 5% (95% CI, 1.6%-11.3%), compared with 13.1% (95% CI, 4.4%-25%) in those with 2 to 4 years of follow-up, and 8.9% (95% CI, 1.1%-21.4%) in those with more than 4 years of follow-up.

Multivariate logistic regression models in the primary studies showed that maximum left atrial volume (hazard ratio, 1.05; 95% CI, 1.02-1.09), left atrial enlargement (relative risk, 6.12; 95% CI, 2.19-17.11), and left atrial diameter (odds ratio, 1.08; 95% CI, 1.01-1.16) were significantly associated with atrial arrhythmias. Atrial ¹⁸F-fluorodeoxyglucose (FDG) uptake was significantly associated with atrial arrhythmias in 2 studies.

Limitations of the study include the absence of randomized controlled trials, and a limited number of studies reported on predictors and outcomes, which resulted in inadequate power to analyze the prognostic implications of atrial arrhythmias among patients with CS. In addition, the varying methods of detecting arrhythmias may have affected outcomes, and it is unclear how the observed heterogeneity and different diagnostic criteria for CS may have affected the findings.

“The AF burden in CS is high and emphasizes the need for close follow-up,” the study authors wrote. “Increased left atrial size and atrial ¹⁸F-FDG uptake are strong independent predictors for the development of atrial arrhythmia. The role of screening for AF and related arrhythmias in this population needs further study as is the predictive accuracy of traditional risk-stratification tools in a relatively younger population.”