Aim: Asymptomatic atrial fibrillation (AF) is frequent and associated with disease progression. This meta-analysis aimed to estimate the prevalence of asymptomatic AF and identify risk factors associated with asymptomatic status.

Methods: MEDLINE(Pubmed), Scopus, Cochrane and ClinicalTrials.gov were searched until January 8, 2025. Double-independent study selection, data extraction and quality assessments were performed. Random-effects meta-analysis was used. Estimates are presented with the asymptomatic individuals in the nominator and the symptomatic patients in the denominator. The assessment of the prevalence of asymptomatic AF and the identification of risk factors associated with the asymptomatic status comprised the main endpoints.

Results: Thirty-seven studies (224273 participants) were included. The prevalence of asymptomatic AF was 27% (95% confidence interval {CI}=[22%,33%]; I2=100%). Risk factors positively associated with the asymptomatic status were male sex (odds ratio {OR}=1.67, 95%CI=[1.48,1.89], p<0.001, I2=85%), diabetes mellitus (OR=1.19, 95%CI=[1.07,1.33], p=0.002, I2=87%), chronic kidney disease (OR=1.21, 95%CI=[1.08,1.36], p<0.001, I2=80%) and stroke/transient ischemic attack (OR=1.43, 95%CI=[1.18,1.73], p<0.001, I2=95%), while heart failure was negatively associated with asymptomatic AF (OR=0.71, 95%CI=[0.54,0.94], p=0.017, I2=97%). Asymptomatic status was also positively associated with permanent AF (OR=2.13, 95%CI=[1.28,3.55]; p=0.004; I2=98%) and negatively associated with catheter ablation (OR=0.63, 95%CI=[0.44,0.91]; p=0.012; I2=95%), beta-blockers (OR=0.90, 95%CI=[0.82,0.98]; p=0.018; I2=68%) and antiarrhythmics (OR=0.53, 95%CI=[0.35,0.79]; p=0.002; I2=95%).

Conclusions: Asymptomatic AF was estimated around 27%, with large variability depending on the prevalence of risk factors associated with asymptomatic status. Asymptomatic individuals had distinct characteristics compared to symptomatic patients, regardless of symptoms' assessment methods and rhythm/rate control interventions. Our results could inform AF screening practices to target asymptomatic individuals.